The Independent Review of Gender Identity Services for Children and Young People (commonly, the Cass Review) was commissioned in 2020 by

NHS England NHS England, formally the NHS Commissioning Board for England, is an executive non-departmental public body of the Department of Health and Social Care. It oversees the budget, planning, delivery and day-to-day operation of the commissioning si ...

and

NHS Improvement NHS Improvement (NHSI) was a non-departmental body in England, responsible for overseeing the National Health Service's foundation trusts and NHS trusts, as well as independent providers that provide NHS-funded care. It supported providers to ...

and led by

Hilary Cass Hilary Dawn Cass, Baroness Cass, (born 19 February 1958), is a British paediatrician. She was the chair of the British Academy of Childhood Disability, established the Rett Clinic for children with Rett syndrome, and has worked to develop pall ...

, a retired consultant paediatrician and the former president of the

Royal College of Paediatrics and Child Health The Royal College of Paediatrics and Child Health, often referred to as the RCPCH, is the professional body for paediatricians (doctors specialising in child health) in the United Kingdom. It is responsible for the postgraduate training of pa ...

. It dealt with gender services for children and young people, including

transgender youth Transgender youth are children or adolescents who do not identify with the Sex assignment, sex they were assigned at birth. Because transgender youth are usually dependent on their parents for care, shelter, financial support, and other needs ...

and those with gender dysphoria in

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

. The final report was published on 10 April 2024, and it was endorsed by both the

Conservative Conservatism is a cultural, social, and political philosophy and ideology that seeks to promote and preserve traditional institutions, customs, and values. The central tenets of conservatism may vary in relation to the culture and civiliza ...

and Labour parties though

LGBT+ Labour LGBT+ Labour is the socialist society (Labour Party), socialist society officially representing the LGBTQ wing of the Labour Party (UK), Labour Party in the United Kingdom. The purpose of the organisation is to campaign within the Labour Party, ...

criticised it. The

Green Party A green party is a formally organized political party based on the principles of green politics, such as environmentalism and social justice. Green party platforms typically embrace Social democracy, social democratic economic policies and fo ...

initially supported the review, but ceased following condemnation from LGBTQ members. LGBTQ advocacy groups in the UK and internationally have criticised the review. The review's recommendations were largely welcomed by UK medical organisations, though some noted criticisms of the review and called for their consideration. The

British Medical Association The British Medical Association (BMA) is a registered trade union and professional body for physician, doctors in the United Kingdom. It does not regulate or certify doctors, a responsibility which lies with the General Medical Council. The BMA ...

called to publicly critique the review and later initiated an independent review of it. The British Association of Gender Identity Specialist and UK's Association of LGBTQ+ Doctors and Dentists criticised the review. Medical organisations outside the UK, international medical organisations, and other countries'

clinical practice guidelines A medical guideline (also called a clinical guideline, standard treatment guideline, or clinical practice guideline) is a document with the aim of guiding decisions and criteria regarding diagnosis, management, and treatment in specific areas of ...

have criticised its methodology, findings, and recommendations. Following high profile media coverage, Cass expressed concern that misinformation about the review had spread online and elsewhere. The review led to a UK ban on prescribing

puberty blocker Puberty blockers (also called puberty inhibitors or hormone blockers) are medicines used to postpone puberty in children. The most commonly used puberty blockers are gonadotropin-releasing hormone (GnRH) agonists, which suppress the natura ...

s to those under 18 experiencing gender dysphoria (with the exception of existing patients or those in a clinical trial). The

Gender Identity Development Service The Gender Identity Development Service (GIDS) was a nationally operated health clinic in the United Kingdom that specialised in working with transgender and gender diverse youth, including those with gender dysphoria. Launched in 1989, GIDS w ...

(GIDS) at the

Tavistock and Portman NHS Foundation Trust The Tavistock and Portman NHS Foundation Trust is a specialist mental health trust based in north London. The Trust specialises in talking therapies. The education and training department caters for 2,000 students a year from the United King ...

was closed in March 2024 and replaced in April with two new services, which are intended to be the first of eight regional centres. In August, the pathway by which patients are referred to gender clinics was revised and a review of adult services commissioned. Text was copied from this source, which is available under a
Open Government Licence v3.0
. © Crown copyright. In September, the Scottish government accepted the findings of a multidisciplinary team that

NHS Scotland NHS Scotland, sometimes styled NHSScotland, is the publicly–funded healthcare system in Scotland and one of the four systems that make up the National Health Service in the United Kingdom. It operates 14 territorial NHS boards across Scotland ...

had set up to consider how the Cass Review's recommendations could best apply there. In England a delayed clinical trial into puberty blockers is planned for 2025.

Background

Referrals to GIDS by assigned sex in each financial year

The

(GIDS) was the specialist clinic nationally commissioned by

to provide care to

transgender A transgender (often shortened to trans) person has a gender identity different from that typically associated with the sex they were sex assignment, assigned at birth. The opposite of ''transgender'' is ''cisgender'', which describes perso ...

and

gender diverse Gender nonconformity or gender variance is gender expression by an individual whose behavior, mannerisms, and/or appearance does not match masculine or feminine gender norms. A person can be gender-nonconforming regardless of their gender identit ...

children, including those with

gender dysphoria Gender dysphoria (GD) is the distress a person experiences due to inconsistency between their gender identitytheir personal sense of their own genderand their sex assigned at birth. The term replaced the previous diagnostic label of gender i ...

. In the years leading up to the Cass Review, several GIDS staff members voiced concerns over the evidence base for the treatments being given and the extent of prior assessment. At the same time, professional disagreements over the strength of evidence for treatments provided to children and young people, such as puberty blockers, was growing. The case of

Bell v Tavistock ''Bell v Tavistock'' was a case before the Court of Appeal (England and Wales) on the question of whether puberty blockers could be prescribed to under-16s with gender dysphoria. ≈ The Court of Appeal said that "it was for clinicians rather ...

also explored issues of informed consent. Several

systematic reviews A systematic review is a scholarly synthesis of the evidence on a clearly presented topic using critical methods to identify, define and assess research on the topic. A systematic review extracts and interprets data from published studies on ...

had found the evidence base supporting these treatments to be poor, and European countries, such as Finland and Sweden, limited the use of puberty blockers and other hormone treatments for this patient cohort, citing a lack of evidence supporting their use. In January 2021, the

Care Quality Commission The Care Quality Commission (CQC) is an executive non-departmental public body of the Department of Health and Social Care of the United Kingdom. It was established in 2009 to regulate and inspect health and social care providers in England. It ...

(CQC) gave GIDS an "inadequate" rating (the lowest one possible). These issues led to GIDS becoming controversial and gaining extensive news coverage. The Cass Review was commissioned by

in September 2020, following a significant increase in referrals to the Gender Identity Development Service and a shift in the service from a

psychosocial The psychosocial approach looks at individuals in the context of the combined influence that psychological factors and the surrounding social environment have on their physical and mental wellness and their ability to function. This approach is ...

and psychotherapeutic model to one that included hormonal treatment. Hilary Cass, a former president of the

(RCPCH), was asked by NHS England and NHS Improvement's Quality and Innovation Committee to chair an independent review with the aim of improving gender identity services for children and young people. The Cass Review's final report stated the concerns which led to its creation included very long waiting lists, of over two years per patient; an "exponential" increase in the number of children and young people requesting

gender-affirming care Transgender health care includes the prevention, diagnosis and treatment of physical and mental health conditions which affect transgender individuals.Gorton N, Grubb HM (2014). General, Sexual, and Reproductive health. In L. Erickson-Schroth. ...

from the NHS; a change towards earlier medical treatment in this patient cohort; and concerns that there was insufficient evidence to justify the treatments being given.

Methodology

The Cass Review was an independent service review which made policy recommendations for services offered to children and young people questioning their gender identity or experiencing gender incongruence in the NHS. Dr. Cass chaired the review and authored its recommendations and reports, independently of any medical bodies or consensus-building process. An assurance group was appointed but was not involved in the preparation of recommendations. No external review or prior consultation was performed before publishing. An advisory board was also established, but the composition and contributions of the group are not documented. The Cass Review commissioned several independent

from the

University of York The University of York (abbreviated as or ''York'' for Post-nominal letters, post-nominals) is a public Collegiate university, collegiate research university in York, England. Established in 1963, the university has expanded to more than thir ...

Centre for Reviews and Dissemination Center or centre may refer to: Mathematics *Center (geometry), the middle of an object * Center (algebra), used in various contexts ** Center (group theory) ** Center (ring theory) * Graph center, the set of all vertices of minimum eccentricity ...

, which were published in ''

Archives of Disease in Childhood ''Archives of Disease in Childhood'' is a peer review, peer-reviewed medical journal published by the BMJ Group and covering the field of paediatrics. It is the official journal of the Royal College of Paediatrics and Child Health. Scope ''Archi ...

''. Whether the research questions were decided by the York Team or Cass Review is unclear. The systematic reviews covered: *Characteristics of children and adolescents referred to specialist gender services *Impact of social transition in relation to gender for children and adolescents *Psychosocial support interventions for children and adolescents experiencing gender dysphoria or incongruence *Interventions to suppress puberty in adolescents experiencing gender dysphoria or incongruence (

puberty blockers Puberty blockers (also called puberty inhibitors or hormone blockers) are medicines used to postpone puberty in children. The most commonly used puberty blockers are gonadotropin-releasing hormone (GnRH) agonists, which suppress the natura ...

) *Masculinising and feminising hormone interventions for adolescents experiencing gender dysphoria or incongruence (

transgender hormone therapy Gender-affirming hormone therapy (GAHT), also called hormone replacement therapy (HRT) or transgender hormone therapy, is a form of hormone therapy in which sex hormones and other hormonal medications are administered to transgender or gender n ...

) *Care pathways of children and adolescents referred to specialist gender services *Clinical guidelines for children and adolescents experiencing gender dysphoria or incongruence The reviews of puberty blockers and gender-affirming hormones excluded qualities deemed to be low quality. The review of psychosocial interventions included all studies regardless of quality. The reviews examined English-language studies of minors, and the quality of studies was assessed using the Mixed Methods Appraisal Tool and a modified version of the Newcastle–Ottawa scale, though certainty-of-evidence ratings were not provided for individual outcomes. Additionally, focus group interviews with patients, clinicians, and a review of previous treatment courses for children and adolescents with gender incongruity in the NHS were conducted.

Interim report

The interim report of the Cass Review was published without peer-review in March 2022. It said the rise in referrals had led to staff being overwhelmed, and recommended the creation of a network of regional hubs to provide care and support to young people. The report said the clinical approach used by the

(GIDS) "has not been subjected to some of the usual control measures" typically applied with new treatments, and raised concerns about the lack of data collection by GIDS. While most children referred to GIDS did not receive endocrine treatment, there was insufficient detail provided about their broader needs when they did. The report said that while the GIDS approach to hormone interventions was initially based on the

Dutch protocol Puberty blockers (also called puberty inhibitors or hormone blockers) are medicines used to postpone puberty in children. The most commonly used puberty blockers are gonadotropin-releasing hormone (GnRH) agonists, which suppress the natura ...

, there were "significant differences" in the current NHS approach. For example, the report said there were no clear guidelines for when to provide psychological support before or instead of medical treatment, endocrinologists administering

s did not attend multidisciplinary meetings, and there was insufficient capacity to increase (or even maintain) appointments once adolescents received puberty blockers. The interim report said GPs and other non-GIDS staff felt "under pressure to adopt an unquestioning affirmative approach" to children unsure of their gender. The report also said that diagnosis of gender-related distress sometimes led to "diagnostic overshadowing", where

comorbidities In medicine, comorbidity refers to the simultaneous presence of two or more medical conditions in a patient; often co-occurring (that is, concomitant or concurrent) with a primary condition. It originates from the Latin term (meaning "sickness" ...

such as poor mental health – which were usually managed by local services – were overlooked. The report suggested that long wait times to access GIDS had resulted in increased distress for patients and their families, as well as less time for exploration – since patients arrived having already begun social transition and with expectations of a rapid assessment process. In response, the

said "being respectful of someone's identity does not preclude exploration", and that it agreed "support should be holistic, based on the best available evidence" without making assumptions about "the right outcome for any given young person". The interim report further said there were "gaps in the evidence" over the use of puberty blockers. A public consultation was held and a further review of evidence by

NICE Nice ( ; ) is a city in and the prefecture of the Alpes-Maritimes department in France. The Nice agglomeration extends far beyond the administrative city limits, with a population of nearly one million In April 2022, Health Secretary

Sajid Javid Sir Sajid Javid (; born 5 December 1969) is a British former politician who served as Secretary of State for Health and Social Care from June 2021 to July 2022, having previously served as Home Secretary from 2018 to 2019 and Chancellor of the ...

told MPs that services in this area were too affirmative and narrow, and "bordering on ideological". In November 2022, the

World Professional Association for Transgender Health The World Professional Association for Transgender Health (WPATH), formerly the Harry Benjamin International Gender Dysphoria Association (HBIGDA), is a professional organization devoted to the understanding and treatment of gender identity and ...

(WPATH) – along with regional groups ASIAPATH, EPATH, PATHA, and USPATH – issued a statement criticising the NHS England interim service specifications based on the interim report.

Final report

The final report of the Cass Review was published on 10 April 2024, alongside a series of systematic reviews and a survey carried out by the

, encompassing the patient cohort, service pathways, international guidelines,

social transitioning Gender transition is the process of Gender affirmation, affirming and Gender expression, expressing one's Gender identity, internal sense of gender, rather than the sex Sex assignment, assigned to them at birth. It is a recommended course of trea ...

s, hormone treatments, and

treatments.

Findings

Lack of research in the field

Quality of relevant studies determined in systematic reviews commissioned by the Cass Review

The report states that the existing evidence for both endocrine (puberty blockers and hormone therapy) and non-endocrine treatments (psychosocial interventions) in children and adolescents with gender incongruence is weak.

Increase in referrals

The report found no clear explanation for the rise in the number of children and adolescents with gender dysphoria, but said there was broad agreement for attribution to a mix of biological and

factors. The report's suggested influences included a lower threshold for medical treatment, social media-related mental health consequences,

abuse Abuse is the act of improper usage or treatment of a person or thing, often to unfairly or improperly gain benefit. Abuse can come in many forms, such as: physical or verbal maltreatment, injury, assault, violation, rape, unjust practices, ...

, access to information regarding

, struggles with emerging sexual orientation, and early exposure to

online pornography Internet pornography or online pornography is any pornography that is accessible over the Internet; primarily via websites, FTP connections, peer-to-peer file sharing, or Usenet newsgroups. The greater accessibility of the World Wide Web from the ...

. The report considered a rise in acceptance of transgender identities to be insufficient to explain the increase on its own.

Social transition

A systematic review evaluated 11 studies assessing the outcomes of social transition in minors using a modified version of the Newcastle-Ottawa scale and considered nine to be low quality and two to be moderate quality. The report said that insufficient evidence was available to assess whether social transition in childhood has positive or negative effects on mental health, and that there was weak evidence for efficacy in adolescence. It also said that sex of rearing seems to influence gender identity, and suggested that early social transition may "change the trajectory" of gender identity development in children. The report said that although social transition was not usually seen as a treatment, it should be considered an "active intervention". It suggests taking "a more cautious approach" for social transition for children than for adolescents, and said pre-pubertal children undergoing social transition should be seen "as early as possible" by an experienced clinician.

Puberty blockers

The report said the evidence base and rationale for early puberty suppression remains unclear, with unknown effects on cognitive and psychosexual development. A systematic review examined 50 studies on the use of puberty blockers using a modified version of the Newcastle–Ottawa scale and rated one as high quality, 25 as moderate quality, and 24 as low quality. The review concluded that the lack of evidence means no conclusions can be made regarding the impact on gender dysphoria and mental health, but did find evidence of bone health being compromised during treatment. The review suggested puberty blockers did not provide children and young people with "time to think", since nearly all patients who went on blockers later proceeded with hormone therapy. For youth assigned male at birth, the report states that blockers taken too early can make a later penile inversion vaginoplasty more difficult due to insufficient penile growth. The report states one of the benefits of puberty blockers is preventing the irreversible changes of a lower voice and facial hair.

Hormone therapy

The report said many unknowns remained for the use of hormone treatment among under-18s, despite longstanding use among transgender adults, with poor long-term follow-up data and outcome information on those starting younger. A systematic review evaluated 53 studies on transgender hormone therapy using a modified version of the Newcastle-Ottawa scale, and rated one study as high quality, 33 as moderate quality and 19 as low quality. Overall, the review found some evidence that hormone treatment improves psychological outcomes after 12 months, but found insufficient evidence regarding physical benefits and risks. The review said hormone therapy should be available from 16 years old, but that there should be a "clear clinical rationale" for the prescription of hormone therapy for anyone under 18.

Psychosocial intervention

A systematic review assessed ten studies on the efficacy of psychosocial support interventions in transgender minors using the Mixed Methods Appraisal Tool and rated one as medium quality, and nine as low quality. The review said that no robust conclusions can be made and more research is needed. The report said the evidence for psychosocial interventions was "as weak as research on endocrine treatment". It recommended that psychosocial interventions also form part of a research programme, along with endocrine interventions.

Clinical pathways

The report said that clinicians cannot be certain which children and young people will have an enduring trans identity in adulthood, and that for most, a medical pathway will not be the most appropriate. When a medical pathway is clinically indicated, wider mental health or psychosocial issues should also be addressed. Due to a lack of follow-up, the number of individuals who detransitioned after hormone treatment was unknown. The Cass Review attempted to work with the

and the NHS adult gender services to "fill some of the gaps in follow-up data for the approximately 9,000 young people who have been through GIDS to develop a stronger evidence base." However, despite encouragement from NHS England, "the necessary cooperation was not forthcoming."

International guidelines

A systematic review assessed 23 regional, national and international guidelines covering key areas of practice, such as care principles, assessment methods and medical interventions. The review said most guidelines lacked editorial independence and developmental rigour, and were nearly all influenced by the 2009

Endocrine Society The Endocrine Society is a professional, international medical organization in the field of endocrinology and metabolism, founded in 1916 as The Association for the Study of Internal Secretions. The official name of the organization was changed t ...

guideline and the 2012 WPATH guideline, which were themselves closely linked. The Cass review questioned the guidelines' reliability, and concluded that no single international guideline regarding transgender care could be applied in its entirety to NHS England.

Conflicting clinical views

The report said there were conflicting views among clinicians regarding appropriate treatment. It suggested that disputes over language such as "exploratory" and "affirmative" approaches meant it was difficult to establish neutral terminology. Some clinicians avoided working with gender-questioning young people. The report said some professionals were concerned about being accused of

conversion therapy Conversion therapy is the pseudoscientific practice of attempting to change an individual's sexual orientation, romantic orientation, gender identity, or gender expression to align with heterosexual and cisgender norms. Methods that have ...

, and were likewise concerned about the impact of legislation to ban conversion therapy.

Recommendations

The report made 32 recommendations covering areas including assessment of children and young people, diagnosis, psychological interventions, social transition, improving the evidence base underpinning medical and non-medical interventions, puberty blockers and hormone treatments, service improvements, education and training, clinical pathways, detransition and private provision. Recommendations included: * Care provision: ** A designated medical practitioner who takes personal responsibility for the safety of children receiving care. ** Individualised care plans, including mental health assessments and screening for neurodivergent conditions such as autism. ** The use of standard psychological and pharmacological treatments for co-occurring and associated conditions like anxiety and depression. ** That children and families considering social transition should be seen as soon as possible by a relevant clinical professional. ** Longstanding gender dysphoria must be a prerequisite for medical transition, but is not the only criteria in deciding whether to allow a transition. ** There should be a clear clinical rationale for the prescription of masculinising/feminising hormone therapy below the age of 18, and no masculinising/feminising hormone therapy below the age of 16. ** Every case considered for medical transition must be discussed by a national multi-disciplinary team. ** All minors should be offered fertility counselling and preservation prior to embarking upon a medical pathway. ** A separate pathway should be established for the treatment of pre-pubertal children, who are ideally to be treated as early as possible. * Changing how the NHS provides care: ** The development of a regional network of centres, and

continuity of care Continuity or continuous may refer to: Mathematics * Continuity (mathematics), the opposing concept to discreteness; common examples include ** Continuous probability distribution or random variable in probability and statistics ** Continuous g ...

for 17–25 year olds. ** The DHSC should direct NHS gender clinics to participate in the data linkage study, with the resulting research being overseen by NHS England's Research Oversight Board. ** A multi-site service network should be developed as soon as possible, and the National Provider Collaborative to oversee the multi-disciplinary team should be established without delay. ** To increase the available workforce, joint contracts should be used for health providers across a wide array of NHS services; and requirements for gender services should be built into the workforce planning for adolescent health services. ** NHS England should develop a formal training program and competency framework for gender services, including a module on the holistic mental assessment framework. ** Similar changes should be considered for adult gender services over the age of 25. ** NHS England should "ensure there is provision for people considering detransition", which may require separate services. ** The DHSC and NHS England should consider the implications of private healthcare on any future requests by patients for treatment under the NHS. ** The DHSC should work to define the dispensing responsibilities of pharmacists receiving private prescriptions, and work to halt the sourcing of transition medication obtained through prescriptions acquired in Europe. * Future research: ** The establishment of a full program of research which will carefully study the characteristics, interventions, and outcomes of every person seen by NHS gender services. ** A central evidence and data resource for gender services should be established, with specifically defined datasets for both local and national services. ** National infrastructure should be put in place to manage continual data collection on gender services, including through the ages of 17 to 25. ** A unified research strategy shall be established to ensure the most meaningful data and numbers are collected. ** A living systematic review over all of this research should be collected. ** The NHS should establish requirements for the collection of data from patients of NHS gender services.

Implementation by NHS England

NHS England responded positively to the interim and final reports. they have implemented a number of measures. In response to the interim report, in March 2024

announced that it would no longer prescribe puberty blockers to minors outside of use in clinical research trials, citing insufficient evidence of safety or clinical effectiveness. GIDS closed in March 2024, being replaced by the new NHS Children and Young People's Gender Services. Two new services, located in the north-west of England and in London, opened in April 2024, and are intended to be the first of up to eight regional services. These will follow a new service specification for the "assessment, diagnosis and treatment of children and young people presenting with gender incongruence". Puberty suppressing hormones are no longer routinely available in NHS youth gender services. New patients that have been assessed as possibly benefiting from them will be required to participate in a clinical trial that is being set up by the

National Institute for Health and Care Research The National Institute for Health and Care Research (NIHR) is the British government's major funder of clinical, public health, social care and translational research. With a budget of over £1.2 billion in 2020–21, its mission is to "impr ...

. A new board, chaired by

Simon Wessely Sir Simon Charles Wessely (born 23 December 1956) is a British psychiatrist. He is Regius Professor of Psychiatry at the Institute of Psychiatry, King's College London and head of its department of psychological medicine, vice dean for academi ...

will encourage further research in the areas highlighted in the review as having a weak evidence base. On August 7, 2024, NHS England announced a status update for young people being considered for referral to specialist gender services, including the publication of a new pathway specification. Referrals will only be accepted from an NHS-commissioned paediatric or children's mental health service instead of general practitioners and other professionals, and those considering social transition should be seen quickly by a clinical professional with relevant experience. NHS England will also "explore the issues around a detransition pathway by October 2024". In April 2025, James Palmer, NHS England's national medical director for specialised services, said the NHS had not issued any new prescriptions of gender affirming hormones to minors in the year since the report's publication, even though they have not been banned, with the NHS instead prioritising "holistic care". Palmer said these new services only have 30 referrals per month, compared to 5,000 per year at GIDS. One paediatric mental health expert said this was due to the increased complexity of the new referral process and families seeking treatment elsewhere — such as by acquiring hormones on the black market or abroad. The clinical trial on puberty blockers for children and young people, due to start late 2024, has now been delayed to 2025. In February 2025, the

(NIHR) revealed that the NHS had commissioned a £10.7 million clinical trial on puberty blockers which is planned to last until 2031. The trial, called "Pathways", will consist of four parts and be led by Emily Simonoff, a head professor of child and adolescent psychiatry at the

King's College London King's College London (informally King's or KCL) is a public university, public research university in London, England. King's was established by royal charter in 1829 under the patronage of George IV of the United Kingdom, King George IV ...

. The trial will involve children being given puberty blockers while having their physical, social and emotional well-being monitored over the span of two years, including regular brain scans to track whether puberty blockers impact their thinking and brain development. Other studies will involve monitoring the well-being of children attending new NHS gender clinics who do not receive puberty blockers. The children also must have the permission of their parents and doctors to participate in the trial. Additionally, the children in the trial will continue to receive psychosocial support and researchers will talk to children about their experiences living with gender dysphoria and the care they receive, as well as getting the opinions of parents and staff. Cass welcomed the news, saying the trial "aims to fill some of the gaps in our knowledge about the outcomes of different interventions".

Reception within the United Kingdom

Response from UK political parties and public bodies

Prime Minister at the time

Rishi Sunak Rishi Sunak (born 12 May 1980) is a British politician who served as Prime Minister of the United Kingdom and Leader of the Conservative Party (UK), Leader of the Conservative Party from 2022 to 2024. Following his defeat to Keir Starmer's La ...

said that the findings "shine a spotlight" on the need for a cautious approach to child and adolescent gender care. In their manifesto for the

2024 United Kingdom general election The 2024 United Kingdom general election was held on Thursday, 4 July 2024 to elect all 650 members of the House of Commons of the United Kingdom, House of Commons. The opposition Labour Party (UK), Labour Party, led by Keir Starmer, won a lan ...

, the Conservatives promised to implement the Cass Review recommendations.

Wes Streeting Wesley Paul William Streeting (; born 21 January 1983) is a British politician who has served as Secretary of State for Health and Social Care since July 2024. A member of the Labour Party, he has been the Member of Parliament (MP) for Ilford ...

, the Labour

shadow A shadow is a dark area on a surface where light from a light source is blocked by an object. In contrast, shade occupies the three-dimensional volume behind an object with light in front of it. The cross-section of a shadow is a two-dimensio ...

Health Secretary at the time, welcomed the final report, saying it was "a watershed moment for the NHS's gender identity services". Both Streeting and then

Shadow Home Secretary In British politics, the shadow home secretary (formally known as the shadow secretary of state for the home department) is the person within the Official Opposition Shadow Cabinet (UK), shadow cabinet who shadows the home secretary; this effecti ...

Yvette Cooper Yvette Cooper (born 20 March 1969) is a British politician who has served as Home Secretary since July 2024. A member of the Labour Party (UK), Labour Party, Cooper has been Member of Parliament (United Kingdom), member of parliament (MP) for Po ...

said Labour would implement the report's recommendations in full. In its statement,

urged their party to "exercise caution in responding to the review", saying that while it got things right, it had "received credible criticism from trans advocacy groups and researchers". In April 2024, the

Green Party of England and Wales The Green Party of England and Wales (GPEW; ), often known simply as the Green Party or the Greens, is a Green politics, green, Left-wing politics, left-wing political party in England and Wales. Since October 2021, Carla Denyer and Adrian Ram ...

released a statement on the review. This was withdrawn an hour later, after the LGBTIQA+ Greens threatened to remove support for their party's leaders. The withdrawal was criticised by

gender-critical Gender-critical feminism, also known as trans-exclusionary radical feminism or TERFism, is an ideology or movement that opposes what it refers to as "gender ideology". Gender-critical feminists believe that sex is biological, immutable, and ...

members. The

Equality and Human Rights Commission The Equality and Human Rights Commission (EHRC) is a non-departmental public body in Great Britain, established by the Equality Act 2006 with effect from 1 October 2007. The Commission has responsibility for the promotion and enforcement of e ...

, a

non-departmental public body In the United Kingdom, non-departmental public body (NDPB) is a classification applied by the Cabinet Office, Treasury, the Scottish Government, and the Northern Ireland Executive to public sector organisations that have a role in the process o ...

, described the Cass Review as a "vital milestone" and called for all service providers to fully implement its recommendations.

Response from devolved governments

The

Scottish Government The Scottish Government (, ) is the executive arm of the devolved government of Scotland. It was formed in 1999 as the Scottish Executive following the 1997 referendum on Scottish devolution, and is headquartered at St Andrew's House in ...

said it would "take the time to consider the findings" of the review.

Humza Yousaf Humza Haroon Yousaf (; born 7 April 1985) is a Scottish politician who served as First Minister of Scotland and Leader of the Scottish National Party (SNP) from March 2023 to May 2024. He served under his predecessor Nicola Sturgeon as Scottish ...

First Minister of Scotland The first minister of Scotland () is the head of government of Scotland. The first minister leads the Scottish Government, the Executive (government), executive branch of the devolved government and is th ...

and

Scottish National Party The Scottish National Party (SNP; ) is a Scottish nationalist and social democratic party. The party holds 61 of the 129 seats in the Scottish Parliament, and holds 9 out of the 57 Scottish seats in the House of Commons of the United Kingdom, ...

(SNP) leader at the time, said the review would be given "utmost consideration", that "all recommendations" made by it would be considered, and that decisions on changes to treatments as a result of the review would be made by clinicians rather than politicians. The

Scottish Greens The Scottish Greens (also known as the Scottish Green Party; ) are a green political party in Scotland. The party has 7 MSPs of 129 in the Scottish Parliament, the party holds 35 of the 1226 councillors at Scottish local Government level. The ...

, then a part of the Scottish Government, criticised the review at its initial publication.

Patrick Harvie Patrick Harvie (born 18 March 1973) is a Scottish politician who served as Minister for Zero Carbon Buildings, Active Travel and Tenants' Rights from 2021 to 2024. He has served as one of two co-leaders of the Scottish Greens since 2008, and i ...

, co-leader of the

, said he'd seen "far too many criticisms" of the review for him to say it was a "valid scientific document". Harvie's comments were controversial and widely critcised, and the resulting tension with the SNP has been cited as a factor in the collapse of the

Bute House Agreement The Bute House Agreement, officially the Cooperation Agreement between the Scottish Government and the Scottish Green Party Parliamentary Group was a Confidence and supply, power-sharing agreement between the Scottish National Party (SNP) Scotti ...

. The Welsh

Senedd The Senedd ( ; ), officially known as the Welsh Parliament in English and () in Welsh, is the devolved, unicameral legislature of Wales. A democratically elected body, Its role is to scrutinise the Welsh Government and legislate on devolve ...

initially voted against a motion tabled by the

Welsh Conservatives The Welsh Conservatives (), also known as the Welsh Conservative Party (), is the branch of the United Kingdom Conservative Party (UK), Conservative Party that operates in Wales. At United Kingdom general elections, Westminster elections, it is ...

Shadow Social Justice Minister to accept the findings of the Cass Review in full. Subsequently, the Senedd voted unanimously to pass an amended motion noting "NHS England has concluded there is not enough evidence to support the safety or clinical effectiveness of puberty suppressing hormones for the treatment of gender dysphoria in children and young people" and "the Welsh Government will continue to develop the transgender guidance for schools taking account of the Cass review and stakeholder views". Citing the Cass Review findings, in August 2024 the

Northern Ireland Executive The Northern Ireland Executive (Irish language, Irish: ''Feidhmeannas Thuaisceart Éireann'', Ulster Scots dialect, Ulster Scots: ''Norlin Airlan Executive'') is the devolution, devolved government of Northern Ireland, an administrative branc ...

agreed to the extension of the ban on the private sale and supply of puberty blockers to Northern Ireland. This was supported by all parties in the Executive at the time apart from the Alliance Party.

Response from health bodies in the United Kingdom

In April 2024, the

British Psychological Society The British Psychological Society (BPS) is a representative body for psychologists and psychology in the United Kingdom. History It was founded on 24 October 1901 at University College London (UCL) as ''The Psychological Society'', the org ...

(BPS) said they supported "the report's primary focus of expanding service capacity across the country" and acknowledged that "while psychological therapies will continue to have an incredibly important role to play in the new services, more needs to be done to assess the effectiveness of these psychological interventions." BPS president Roman Raczka said the review was "thorough and sensitive", and welcomed the recommendation for a consortium of relevant bodies to develop better trainings and upskill the workforce. Rob Agnew, chair of the BPS's Sexualities Section, described it as "bad news for our trans youth" and said it was "out of step with better quality, more comprehensive reviews". The

Royal College of Psychiatrists The Royal College of Psychiatrists is the main professional organisation of psychiatrists in the United Kingdom, and is responsible for representing psychiatrists, for psychiatric research and for providing public information about mental healt ...

(RCP) welcomed the report. They supported the emphasis on a holistic and person-centred approach and research to improve the evidence basis for treatment protocols. They said that some of its trans members, and the wider trans community, had concerns about availability of treatments while awaiting research, said there was "a strong view that the report makes assumptions in areas such as social transition and possible explanations for the increase in the numbers of people who have a trans or gender diverse identity, which contrasts with the more decisive statements about treatment approaches", and called for direct and comprehensive involvement of those with lived experience. The

(RCPCH) said they would take the time to review the recommendations in full and said that data collected had identified a lack of confidence by paediatricians and GPs to support this patient group, which the RCPCH pledged to address by developing new training. In August 2024, the RCPCH acknowledged there had been some academic criticism of the Cass Review and a call to pause the implementation of recommendations, but that "pausing the implementation of the Cass report recommendations would be a backwards step for Gender Identity Services, as this will again delay care and therefore risks causing further harm to this patient population". They stated they were engaged with NHS England and as a part of this would "encourage NHSE to consider emerging criticisms of any chosen approach, as would be the case in the delivery of any other children's health service." In July 2024, the

Royal College of General Practitioners The Royal College of General Practitioners (RCGP) is the professional body for general (medical) practitioners (GPs/ Family Physicians/ Primary Care Physicians) in the United Kingdom. The RCGP represents and supports GPs on key issues including ...

updated its position statement on the role of the GP in transgender care in response to the Cass Review. They advise that, for patients under 18, GPs should not prescribe puberty blockers outside of clinical trials, and the prescription of gender-affirming hormones should be left to specialists. The GCGP says it will fully implement the Cass Review recommendations. They specifically highlight recommendations for continuity of care for 17–25 year olds, and the need for additional services for those people considering detransition. The same month Vassili Crispi, a member of the governing council of the

(BMA) and member of its LGBTQ+ network, brought a motion calling for the BMA to initiate an evidence-based critique of the review's methodology and oppose the governments legislative approach. He later stated the Cass Review was commissioned, funded, and published "by an openly gender-critical government", representing a conflict of interest. The BMA, which represents 190,000 doctors, passed the motion calling for the organisation to "publicly critique" the Cass Review and oppose the implementation of its "unsubstantiated recommendations". After the motion was leaked to journalist Hannah Barnes, more than 1,500 doctors (including nearly 1,000 BMA members) signed an open letter to the BMA which criticised the council for "going against the principles of evidence-based medicine and against ethical practice". In September 2024, the BMA council voted to instead maintain a neutral position on the issue until the completion of its own evaluation of the Cass Review. The

Academy of Medical Royal Colleges The Academy of Medical Royal Colleges (AoMRC) is the coordinating body for the United Kingdom and Ireland's 23 Medical Royal Colleges and Faculties. It ensures that patients are safely and properly cared for by setting standards for the way doct ...

(AoMRC) released a statement in August 2024 in support of the report's recommendations, stating that "further speculative work risks greater polarisation", and that "our focus should be on implementing the recommendations of the Cass Review".

Response from LGBTQ health bodies in the UK

In April 2024, the British Association of Gender Identity Specialists (BAGIS) said it was "deeply troubled by some of the content of the Cass Review and the potential impact thereof". In December 2024, BAGIS also said it was "dismayed" to see the Department for Health and Social Care's "indefinite ban" on

s for under-18s, stating: "The Cass Review finds that puberty blockers have clearly defined benefits in narrow circumstances, which is inconsistent with a legislative ban". In July 2024, the UK's Association of LGBTQ+ Doctors and Dentists (GLADD) criticised the

British Medical Journal ''The BMJ'' is a fortnightly peer-reviewed medical journal, published by BMJ Publishing Group Ltd, which in turn is wholly-owned by the British Medical Association (BMA). ''The BMJ'' has editorial freedom from the BMA. It is one of the world ...

's coverage of the Cass Review, stating that some recommendations could be beneficial while others could create new barriers to care for transgender youth. It also criticised "The weaponisation of the Cass review against trans people" by political parties and campaigners. In October, GLADD released an official response to the review, stating they were broadly supportive of its recommendations but were "concerned with what we believe to be an ingrained bias against the autonomy of trans people throughout the narrative text" which had also been noted by others. Of the 32 recommendations of the Cass Review, GLADD supported 15, and said that it could support a further 14 with provisos, could not support two, and was neutral on one. GLADD also said the Cass Review "may implicitly pathologise trans and non-binary identities" or "perpetuate stigmatisation of this population", including in its discussions of social transition, the suggestion that gendered toy preference is biologically deterministic, and the language used regarding masculinising/feminising hormones as a negative or undesirable outcome.

Hilary Cass's response

In an interview given the week after the release of the final report, Cass described receiving abusive emails and said she was given security advice to avoid public transport. She said that "disinformation" had frequently been spread online about the report. Cass said deliberate attempts "to undermine a report that has looked at the evidence of children's healthcare" were "unforgivable" and put children at risk. There were widespread misleading claims from critics of the report that it had dismissed 98% of the studies it collected and all studies which were not

double-blind In a blind or blinded experiment, information which may influence the participants of the experiment is withheld until after the experiment is complete. Good blinding can reduce or eliminate experimental biases that arise from a participants' expec ...

experiments. Cass described these claims as being "completely incorrect". Although only 2% of the papers collected were considered to be of high quality, 60% of the papers, including those considered to be of moderate quality, were considered in the report's evidence synthesis. Cass criticised Labour MP

Dawn Butler Dawn Petula Butler (born 3 November 1969) is a British Labour Party politician who is member of parliament (MP) for Brent East. She previously served as MP for Brent Central (2015–2024) and Brent South (2005–2010). Born in London to Jama ...

for repeating inaccurate claims that the review had dismissed more than 100 studies during a debate in the

House of Commons The House of Commons is the name for the elected lower house of the Bicameralism, bicameral parliaments of the United Kingdom and Canada. In both of these countries, the Commons holds much more legislative power than the nominally upper house of ...

. After talking with Cass, Butler used a

point of order In parliamentary procedure, a point of order occurs when someone draws attention to a rules violation in a meeting of a deliberative assembly. Explanation and uses In ''Robert's Rules of Order, Robert's Rules of Order Newly Revised'' (RONR), a ...

to admit her mistake and correct the record in Parliament, stating the figure came from a briefing she had received from Stonewall. In a May 2024 interview with ''

The New York Times ''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of ...

'', Hilary Cass said: She also said that the review was not about defining what trans means or rolling back healthcare, stating: "There are young people who absolutely benefit from a medical pathway, and we need to make sure that those young people have access — under a research protocol, because we need to improve the research — but not assume that that's the right pathway for everyone." In a May 2024 interview with ''

WBUR-FM WBUR-FM (90.9 FM) is a public radio station located in Boston, Massachusetts, owned by Boston University. Its programming is also known as WBUR News. The station is the largest of three NPR member stations in Boston, along with WGBH and W ...

'', Cass responded to WPATH's criticism about prioritising non-medical care, saying the review did not take a position about which is best. Cass hoped that "every young person who walks through the door should be included in some kind of proper research protocol" and for those "where there is a clear, clinical view" that the medical pathway is best will still receive that, and be followed up to eliminate the "black hole of not knowing what's best". Responding to claims that the review assumed a trans outcome was the worst outcome for a child, Cass emphasised that a medical pathway, with lifetime implications and treatment, required caution but "it's really important to say that a cis outcome and a trans outcome have equal value".

Global reception

Professional organisations and transgender health providers have widely criticised the Review's findings.

Global health bodies

The

responded to the report by reaffirming their support for gender-affirming care for minors and saying that their current policies supporting such treatments are "grounded in evidence and science". The Endocrine Society said the Review "does not contain any new research that would contradict the recommendations made in our Clinical Practice Guideline on gender-affirming care" and concluded "Banning evidence-based medical care based on misinformation takes away the ability of parents and patients to make informed decisions.". The

(WPATH) released an email statement saying the report is "rooted in the false premise that non-medical alternatives to care will result in less adolescent distress" and further criticised recommendations which "severely restrict access to physical healthcare, and focus almost exclusively on mental healthcare for a population which the

World Health Organization The World Health Organization (WHO) is a list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Gen ...

does not regard as inherently mentally ill". An official statement expanded on these concerns, saying Hilary Cass had "negligible prior knowledge or clinical experience" and that "the (research and consensus-based) evidence" suggests medical treatments such as puberty blockers and hormone therapy were "helpful and often life-saving". It questioned the provision of puberty blockers only in the context of a research protocol: "The use of a randomized blinded control group, which would lead to the highest quality of evidence, is ethically not feasible." In 2022, WPATH, ASIAPATH, EPATH, PATHA, and USPATH, responding to the NHS policy changes arising from the Interim Report, had stated they "makes assumptions about transgender children and adolescents which are outdated and untrue" including "the supposition that gender incongruence is transient in pre-pubertal children", arguing it "quotes selectively and ignores newer evidence about the persistence of gender incongruence in children" in addition to noting issues with the older studies. They further said the statement "the primary intervention for children and young people... is psychosocial (including psychoeducation) and psychological support and intervention" was alarming. They said "this 'psychotherapeutic' approach, which was used for decades before being superseded by evidence-based gender-affirming care, has not been shown to be effective. Indeed, the denial of gender-affirming treatment under the guise of ' exploratory therapy' has caused enormous harm to the transgender and gender diverse community and is tantamount to 'conversion' or 'reparative' therapy under another name". International transgender healthcare bodies, other international organisations, researchers, and politicians have also criticised the recommendation that children and young people accessing puberty blockers should be required to sign up to a research trial.

Australia and New Zealand

The

Royal Australian and New Zealand College of Psychiatrists The Royal Australian and New Zealand College of Psychiatrists (RANZCP) is the principal organisation representing the medical specialty of psychiatry in Australia and New Zealand and has responsibility for training, examining and awarding the qua ...

rejected calls for an inquiry into trans healthcare following the release of the Cass Review, characterising it as one review among several in the field. They emphasised that, "assessment and treatment should be patient centred, evidence-informed and responsive to and supportive of the child or young person's needs and that psychiatrists have a responsibility to counter stigma and discrimination directed towards trans and gender diverse people." The Professional Association for Transgender Health Aotearoa (PATHA), a New Zealand professional organisation, said the Cass Review made "harmful recommendations" and was not in line with international consensus. It suggested that "Restricting access to social transition is restricting

gender expression Gender expression (or gender presentation) is a person's behavior, mannerisms, interests, and appearance that are associated with gender in a particular cultural context, typically understood in terms of masculinity and femininity. Gender expr ...

, a natural part of human diversity". It also said trans or non-binary people were not included in the Cass Review's planning and decision-making – including clinicians experienced with affirmative care – while several people involved in the review had "previously advocated for bans on

" in the U.S., and had "promoted non-affirming '

gender exploratory therapy Conversion therapy is the pseudoscientific practice of attempting to change an individual's sexual orientation, romantic orientation, gender identity, or gender expression to align with heterosexual and cisgender norms. Methods that have been ...

', which is considered a conversion practice". PATHA criticised the exclusion of those with clinical and lived experience of gender-affirming care from "its decision-making, conclusions, or findings" and the exclusion of trans people from the review's Governance Assurance Group "on the basis of potential bias". A joint statement by Equality Australia, signed by the Australian Professional Association for Trans Health (AusPATH) and PATHA among others, said the review "downplays the risk of denying treatment to young people with gender dysphoria and limits their options by placing restrictions on their access to care".

Canada

The Canadian Pediatric Society responded that "Current evidence shows puberty blockers to be safe when used appropriately, and they remain an option to be considered within a wider view of the patient's mental and psychosocial health." Members of the Canadian Pediatric Society's Adolescent Health Committee stated "there are significant limitations, biases, and inaccuracies within the Review", that "the Review has been noted to include incorrect citations of evidence (6) and inaccurate, sometimes scientifically disproven speculations", and concluded "The Cass Review is a critique, authored by a single individual, presenting a perspective on current practices in a particular context, and it will inform care. It does not, however, purport to be 'the new international standard of care', and it should not be treated as such."

Europe

In June 2024, the European Society for Child and Adolescent Psychiatry (ESCAP) issued a statement which referred to the Cass Review systematic reviews along with previous reviews conducted in the UK, Sweden, Finland and Germany which also found a lack of evidence for the safety or efficacy of puberty blockers and cross-sex hormones to treat minors with gender dysphoria. ESCAP stated that "there is an urgent need to apply widely endorsed clinical, scientific, and ethical standards to the care of children and adolescents with gender dysphoria", called for healthcare providers "not to promote experimental and unnecessarily invasive treatments with unproven psycho-social effects", and insisted on the importance of "respect for all kinds of different views and attitudes" in professional debate. In September 2024, in reference to the NHS' planned implementation of this recommendation that puberty blockers be restricted to clinical trials, as well as a similar protocol in Sweden, a thematic report prepared by the

Council of Europe The Council of Europe (CoE; , CdE) is an international organisation with the goal of upholding human rights, democracy and the Law in Europe, rule of law in Europe. Founded in 1949, it is Europe's oldest intergovernmental organisation, represe ...

Committee of Experts on Sexual Orientation, Gender Identity and Expression, and Sex Characteristics (ADI-SOGIESC) said: "There are ethical implications of only offering treatment to a small group of patients, potentially violating the fundamental ethical principles governing research ... as for many young people the only way to receive treatment is to participate in the trial, therefore calling into question whether consent can be constituted as free and informed in these situations".

Germany, Austria, and Switzerland

In 2025 a collaboration of Germany, Austria, and Switzerland, led by the

Association of the Scientific Medical Societies in Germany The Association of the Scientific Medical Societies in Germany (AWMF; ''Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften''), established in 1962 and located in Frankfurt am Main, is the umbrella organisation of more than ...

, produced new

on transgender healthcare which criticised the Cass Review's methodology, conclusions, and lack of transparency. The guidelines stated there are "no proven effective treatment alternative without body-modifying medical measures for a erson withpermanently persistent gender incongruence" and criticised the potentially harmful recommendation of psychotherapy for distress related to gender dysphoria as no studies in the review showed a reduction in dysphoria through psychotherapy. It further criticised the Cass Review's lack of involvement from medical professional societies, its "assurance group" being explicitly uninvolved in the development of recommendations, and the presence of an "advisory board" whose composition and contributions weren't documented.

Japan

In August 2024, the published updated guidelines on the treatment of gender dysphoria. The guidelines considered the Cass Review, describing it as specific to the unique situation in the UK, noted criticism of the Cass Review by other international organisations, and stated that the WPATH SOC8 considered more systematic reviews. The guidelines further said it is "self-evident" that, unless puberty is suppressed, development of sex characteristics are irreversible in AMAB individuals. The society stated they will continue to track and recommend prescriptions of puberty blockers in Japan to minors and expand to tracking discontinuations and switches to hormone therapy.

Netherlands

The Amsterdam University Medical Center said it agrees with the goals of reducing wait times and improving research, but disagrees that the research-base for puberty blockers is insufficient, stating that puberty blockers have been used in trans care for decades. It stated they did not consider it ethical to mandate youth who desire puberty blockers to be registered in research trials, that it was worrying that after closing GIDS youth seeking trans healthcare were deprived of care, and that it "regrets that this situation arose for patients in England."

Poland

A Polish ''Framework guidelines for the process of caring for the health of adolescent transgender (T) and non-binary (NB) people experiencing gender dysphoria'' was released in 2024 which said the Cass Review "caused a stir in public opinion and immediate harsh criticism from the medical and patient communities worldwide" and criticised Cass being chosen for her lack of experience in trans healthcare. It stated "the common thread of many objections to the Cass report is the multifaceted downplaying of the importance of the voices of adolescents and their families, clinical practice, the scientific knowledge base, and national and global recommendations, while misleading the public that a complete lack of clinical experience in a given field is a guarantee of reliability."

United States

The

American Academy of Pediatrics The American Academy of Pediatrics (AAP) is the largest professional association of pediatricians in the United States. It is headquartered in Itasca, Illinois, and maintains an office in Washington, D.C. The AAP has published hundreds of poli ...

responded to the report by reaffirming its support for gender-affirming care for minors and saying that their current policies supporting such treatments are "grounded in evidence and science". The

American Psychological Association The American Psychological Association (APA) is the main professional organization of psychologists in the United States, and the largest psychological association in the world. It has over 170,000 members, including scientists, educators, clin ...

stated they were studying the Cass report but "stand by" their position statement in support of gender-affirming care. In May 2025, the

United States Department of Health and Human Services The United States Department of Health and Human Services (HHS) is a cabinet-level executive branch department of the US federal government created to protect the health of the US people and providing essential human services. Its motto is ...

under President

Donald Trump Donald John Trump (born June 14, 1946) is an American politician, media personality, and businessman who is the 47th president of the United States. A member of the Republican Party (United States), Republican Party, he served as the 45 ...

released a report in compliance with a January executive order forbidding the government from supporting gender transitions under 19. The report expressed support for the Cass Review and its findings, which it cited extensively, calling it the "most comprehensive" and "most influential" evaluation of youth gender affirming care to date.

Reception by academics and researchers

Some academics in the UK agreed with the Cass Review's findings stating a lack of evidence; others, both in the UK and internationally, disagreed with the report's methodology and findings. Several scholars and organisations have criticised the Cass Review's conclusions and the evidence base used to support them. Researchers Cal Horton and Ruth Pearce have said of the Cass Review, "its most controversial recommendations are based on prejudice rather than evidence". Cal Horton criticised the Interim Report and other documents for prioritising research on aetiology of trans identities, saying: "Research into the causation of trans identities has a pathologized history, running parallel to efforts to prevent or cure transness." Cal Horton also criticised the Interim Report's support of exploratory therapy and its use of the terminology of "desistance". Various scholars also criticised the emphasis on high and moderate quality evidence, saying that paediatric care often relies on low quality evidence in other areas; that in downgrading qualitative research, the patient voice was minimised; and that the highest quality evidence (such as from

randomised controlled trials A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical t ...

) may be difficult or unethical to obtain in this area. Academics have also criticised unsupported claims that social transition and puberty blockers may "change the trajectory of psychosexual and gender identity development" and that youth who transition may lose the opportunity to experience adulthood as a gender they don't identify with. In September 2024, a commentary was published in

Journal of Adolescent Health The ''Journal of Adolescent Health'' is a peer-reviewed medical journal covering adolescent health and medicine, including biological, psychological, and social aspects. The journal publishes original research articles, review articles, letters to ...

arguing that other scholars had made "lengthy and nuanced rebuttals to the Cass report". The commentary says that Cass' conclusions generally focus on "limiting or minimizing medical

(GAC) for youth" and that she "minimizes the robust data and the potential negative impact of increasing barriers for an already disenfranchised group". The commentary states that "GAC for youth is well supported by evidence" and that concerns about the evidence base and the need for more research "do not warrant removal of access to this important care". The commentary further suggests that

(RCT) would not be ethically feasible for young people experiencing gender dysphoria. In November 2024, over 200

educational psychologists Educational psychology is the branch of psychology concerned with the scientific study of human learning. The study of learning processes, from both cognitive and behavioral perspectives, allows researchers to understand individual differences in ...

signed an open letter addressed to education secretary

Bridget Phillipson Bridget Maeve Phillipson (born 19 December 1983) is a British politician who has served as Secretary of State for Education and Minister for Women and Equalities since July 2024. A member of the Labour Party, she has been the Member of Parli ...

. The letter expressed concerns about the "processes and findings of the Cass review" and the impact of the Cass Review on children and young people in education. That same month, the healthcare division of the

RAND Corporation The RAND Corporation, doing business as RAND, is an American nonprofit global policy think tank, research institute, and public sector consulting firm. RAND engages in research and development (R&D) in several fields and industries. Since the ...

(a US-based research institute), released its own systematic review into treatments for trans and gender expansive young people, in which it described several similarities and differences between its own approach and that of the Cass Review. The report rated the existing evidence base as having low and very low certainty, but also found the treatments to be low risk and with little evidence of side-effects, regret, or dissatisfaction. It said the Cass Review was "highly comprehensive", but said its findings may have limited applicability outside the context of the NHS. On 9 May 2025 a critical evaluation of the Cass report and its seven commissioned reviews was published in '' BMC Medical Research Methodology''. Using an independent Risk of Bias (ROBIS) tool, the evaluation identified a "high risk of bias" in all seven reviews as well as "methodological flaws", "unsubstantiated claims", and "misrepresentation of evidence".

Yale Law School Integrity Project

In July 2024, The Integrity Project at

Yale Law School Yale Law School (YLS) is the law school of Yale University, a Private university, private research university in New Haven, Connecticut. It was established in 1824. The 2020–21 acceptance rate was 4%, the lowest of any law school in the United ...

released a white paper which said the Cass Review had "serious flaws". The white paper, co-authored by a group of eight legal scholars and medical researchers, suggests that the Cass Review "levies unsupported assertions about gender identity, gender dysphoria, standard practices, and safety of gender-affirming medical treatments, and it repeats claims that have been disproved by sound evidence". It concluded that the review "is not an authoritative guideline or standard of care, nor is it an accurate restatement of the available medical evidence on the treatment of gender dysphoria." The white paper criticised the review's recruitment for focus groups, which included individuals who were not clinicians and who had unclear expertise, and said that the review "is not an accurate restatement of the available medical evidence on the treatment of gender dysphoria". In reference to one question, where a third of respondents agreed with the statement "There is no such thing as a trans child", the authors write: "Denying the existence of transgender people of any age is an invalid professional viewpoint. The involvement of those with such extreme viewpoints is a deeply concerning move for a document that issues recommendations on clinical care." The Yale Integrity Project white paper suggested that what the Cass Review referred to as the "exponential change in referrals" to youth gender services was not actually exponential, and that the recorded growth could be the result of double counting data points. Further, the paper criticises the Cass Review for suggesting that "peer and socio-cultural influence" are driving the increase in referrals, a claim which originates from a single article that has been heavily corrected for numerous well-documented fatal flaws. The Cass Review also suggested that the provision of gender-affirming care appeared "rushed, careless, and common", though its data showed waiting times for assessment were over two years and only 27% of patients seen during the review were referred to endocrinology for consideration of medical intervention. The Yale Integrity Project also criticised the review's discussions of evidence quality, since it introduces the

GRADE approach The GRADE approach (Grading of Recommendations Assessment, Development and Evaluation) is a method of assessing the certainty in evidence (also known as quality of evidence or confidence in effect estimates) and the strength of recommendations in ...

and uses its terminology but does not evaluate evidence using the GRADE framework, and "takes the unusual step of elevating its own assessment of evidence quality above the considerations that guideline developers value".

Reception by advocacy organisations

Amnesty International Amnesty International (also referred to as Amnesty or AI) is an international non-governmental organization focused on human rights, with its headquarters in the United Kingdom. The organization says that it has more than ten million members a ...

criticised "sensationalised coverage" of the review, stating it was "being weaponised by people who revel in spreading disinformation and myths about healthcare for trans young people".

LGBTQ organisations

The

International Lesbian, Gay, Bisexual, Trans and Intersex Association The International Lesbian, Gay, Bisexual, Trans and Intersex Association (ILGA, Spanish: ''Asociación internacional de lesbianas, gays, bisexuales, trans e intersexuales'') is a LGBTQ+ rights organization. It participates in a multitude of a ...

(ILGA), international LGBTQ student organisation

IGLYO The International Lesbian, Gay, Bisexual, Transgender, Queer & Intersex Youth and Student Organisation (IGLYO) is an international LGBTQI organisation that was created in 1984 as a reaction to the need for better cooperation among regional, local ...

, and

Transgender Europe Transgender Europe (TGEU) is a network of different organisations working to combat discrimination against trans people and support trans people rights. It was founded in 2005 in Vienna during the 1st European Transgender Council as "European Tr ...

released a joint statement which criticised the Cass Review's "poor and inconsistent use of evidence, pathologising approaches, and exclusion of service users and trans healthcare experts", as well as the review's exclusion of service users and trans healthcare experts. ILGA and Transgender Europe also raised concerns about "pathologizing approaches" and the use of language like "gender questioning" to refer to transgender youth. Trans youth charity

Mermaids In folklore, a mermaid is an aquatic creature with the head and upper body of a female human and the tail of a fish. Mermaids appear in the folklore of many cultures worldwide, including Europe, Latin America, Asia, and Africa. Mermaids are ...

and the LGBTQ+ charity Stonewall endorsed some of the report's recommendations, such as expanding service provisions with the new regional hubs, but raised concerns the review's recommendations may lead to barriers for transgender youth in accessing care. In October 2024, 100 LGBTQ+ organisations and activists signed a letter to Wes Streeting expressing a "deep lack of confidence" in the Review. Concerns included Cass's selection without consideration of other candidates, "secrecy" regarding the report's commissioning, and "explicit exclusion of any trans people from involvement in the Governance Assurance Group, on the basis of potential bias". It described the review as "an absurd spectacle" with extensively documented technical failings and said, "There is a real concern, therefore, that the review promotes an inherently flawed approach to determining the efficacy and safety of clinical support for trans healthcare". Trans advocates have criticised the Cass Review for its alleged connections with anti-trans activism. LGBTQ advocates specifically criticised meetings between Cass, members of her team, and members of Florida governor

Ron DeSantis Ronald Dion DeSantis (; born September 14, 1978) is an American politician, attorney, and former United States Navy, naval officer serving as the 46th List of governors of Florida, governor of Florida since 2019. A member of the Republican Pa ...

' medical board, which restricted transgender healthcare in Florida. Cass met with board member Patrick Hunter, a member of the

Society for Evidence-Based Gender Medicine The Society for Evidence-Based Gender Medicine (SEGM) is a non-profit organization that is known for its opposition to gender-affirming care for transgender youth and for engaging in political lobbying. SEGM is known for transgender health care ...

(SEGM) and

Catholic Medical Association The Catholic Medical Association (CMA) is an organization of Catholic physicians, dentists, and health care professionals. This article refers to the organisation operating in the United States and Canada. it had about 900 members. Until 1997, i ...

. Hunter and Cass exchanged materials and Cass was invited to present to the board.

Unions

In June 2024, the University and College Union's (UCU) national executive committee unanimously passed a motion criticising the review's methodology, sourcing and claims. This was met with criticism from some academics and union members, who said the move "risks making the union appear anti-scientific". The UCU brought a version of the motion to the

Trades Union Congress The Trades Union Congress (TUC) is a national trade union center, national trade union centre, a federation of trade unions that collectively represent most unionised workers in England and Wales. There are 48 affiliated unions with a total of ...

(TUC) LGBT+ conference, where it was carried without opposition.

Reception by gender-critical organisations

Gender-critical Gender-critical feminism, also known as trans-exclusionary radical feminism or TERFism, is an ideology or movement that opposes what it refers to as "gender ideology". Gender-critical feminists believe that sex is biological, immutable, and ...

organisations including Sex Matters and

Genspect Genspect is an international group founded in June 2021 by psychotherapist Stella O'Malley that has been described as gender-critical. Genspect opposes gender-affirming care, as well as social and medical transition for transgender people. Gen ...

welcomed the report. Stella O'Malley of Genspect said that if a

ban were to criminalise any exploration into why a child identifies as trans, it "would ban the very therapy that Cass is saying should be prioritised".

Subsequent government actions in the UK

Ban on puberty blockers

Private prescription

In May 2024, then Health Secretary

Victoria Atkins Victoria Mary Atkins (born 22 March 1976) is a British politician who served in various ministerial positions under Prime Ministers Theresa May, Boris Johnson and Rishi Sunak between 2017 and 2024, lastly as Secretary of State for Health and S ...

implemented an emergency three-month ban on the prescription of puberty blockers by medical providers outside of the NHS. It went into effect on 3 June 2024 and was set to expire on 3 September 2024. The ban restricted their use to those already taking them, or within a clinical trial. In July, this ban was challenged by campaign groups TransActual and the

Good Law Project The Good Law Project is a United Kingdom-based political non-profit company. Founded by Jolyon Maugham, the Good Law Project states that its mission is to achieve change and government accountability through the law. History The Good Law Projec ...

who brought a legal case arguing the ban was unlawful. On 29 July 2024, the

High Court of Justice The High Court of Justice in London, known properly as His Majesty's High Court of Justice in England, together with the Court of Appeal (England and Wales), Court of Appeal and the Crown Court, are the Courts of England and Wales, Senior Cour ...

ruled that the ban was lawful. The Health Secretary

welcomed the decision as "evidence led", and said efforts were being made to set up a clinical trial to "establish the evidence on puberty blockers". Following the ruling, TransActual announced they would not appeal the decision due to limited funds and the unlikelihood of an appeal being heard before the ban expires. On 22 August 2024, the government extended the emergency ban until 26 November 2024. The ban was also extended to cover Northern Ireland, following agreement from the Northern Ireland Executive and came into effect on 27 August 2024. On 6 November 2024 the ban was extended again to 31 December 2024. On 11 December 2024, the ban was renewed indefinitely and is set to be reconsidered in 2027.

Commission on Human Medicines review

In January 2025, the

Commission on Human Medicines The Commission on Human Medicines (CHM) is a committee of the UK's Medicines and Healthcare products Regulatory Agency. It was formed in October 2005, and assumed the responsibilities of the Medicines Commission and the Committee on Safety of Med ...

(CHM) delivered a report on the proposed permanent restriction of the use of puberty blockers for children and young people. The review stated that both "Baroness Cass and the independent CHM found that there is a lack of evidence for the efficacy of these medicines in the treatment of gender incongruence and/or gender dysphoria, and that there is currently an unsafe prescribing environment." The report recommended an indefinite ban until prescriptions could be deemed safe, with legislation to be reviewed in 2027. According to the report, the proposed ban was opposed by the Royal College of General Practitioners, the British Medical Association and the

Ban on cross-sex hormones

In May 2025, Government lawyers confirmed that Wes Streeting was "actively reviewing" a potential ban on prescription of cross-sex hormones to under-18s, with an expert panel due to deliver a report on the matter in July.

Adult clinics

The Cass Review did not cover adult care, but in April 2024, NHS England said it would also initiate a review of adult gender clinics. NHS England National Director of Specialised Commissioning John Stewart sent a letter to Cass stating that it would review the use of

in adults in a similar manner as was done for puberty blockers in the Cass Review. In May 2024, Cass wrote to NHS England to pass on the feedback regarding adult care from clinicians who had approached her during the review process. Clinicians across the country in adult gender services had expressed concern about both the clinical practice and model of care. Some clinicians in other settings, especially general practice, had raised concerns about the treatment of patients under their care. On 7 August, NHS England included a response to the adult care letter in a status report for the under-18s services. On 8 August, they stated the review of adult services would be led by Dr. David Levy, medical director for Lancashire and South Cumbria integrated care board, to assess "the quality (i.e. effectiveness, safety, and patient experience) and stability of each service, but also whether the existing service model is still appropriate for the patients it is caring for"; and that Dr. Levy would work with a group of "expert clinicians, patients and other key stakeholders, including representatives from the CQC, Royal Colleges and other professional bodies and will carefully consider experiences, feedback and outcomes from clinicians and patients, past and present". The first onsite visits are planned to start in September 2024. The findings will be used to support an updated adult gender service specification which will then be liable to engagement and public consultation. Unlike the Cass Review, the review of adult gender services is expected to be completed within months, rather than years. In December 2024, it was reported that a number of GPs had begun refusing or withdrawing hormone treatment from adult trans patients, for reasons including insufficient funds, the Cass Review, and the Royal College of GPs' response to the Cass Review – despite the Cass Review only applying to youth services.

NHS Scotland

On 18 April 2024,

announced that it had paused prescribing puberty blockers to children referred by its specialist gender clinic. The chief medical officer of Scotland set up a multidisciplinary clinical team to assess how the Cass Review's 32 recommendations might be applied to

. Their ''Cass Review – implications for Scotland: findings report'' was published in July 2024 and found that the majority of recommendations were applicable to NHS Scotland to a varying degree, with some modification dealing with differences in the Scottish health service. They recommended that the use of puberty blockers be paused until clinical trials are begun. NHS Scotland will participate in the forthcoming UK study. That report was fully accepted by the Scottish government in September. Among the changes recommended are that the gender identity service for children and young people should be moved to a paediatric setting and more than one service offered across the regions. In common with other specialities, a referral to these services will now have to come from a clinician.

Department for Education

In May 2024, the UK government released a draft of new Relationships, Sex and Health Education (RSHE) guidelines. The guidelines would ban lessons on the "contested theory of gender identity" and emphasised that any instruction on transgender people must focus on the legality of transitioning and the fact one has to be 18 to legally change their gender. A press release accompanying the guidelines stated that "In light of the Cass Review, it is important that schools take a cautious approach to teaching about this sensitive topic and do not use any materials that present contested views as fact, including the view that gender is a spectrum."

Endnotes

References

Works cited

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External links

* {{Official website, https://cass.independent-review.uk/ Transgender health care National Health Service (England) 2024 in England 2024 in health 2024 in LGBTQ history Health policy in the United Kingdom Transgender topics in England Transgender history in the United Kingdom Works about health care LGBTQ-related controversies in the United Kingdom Reports of the United Kingdom government