A psychoactive drug, psychopharmaceutical, mind-altering drug, consciousness-altering drug, psychoactive substance, or psychotropic substance is a

chemical substance A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be com ...

that alters psychological functioning by modulating

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

activity. Psychoactive and psychotropic drugs both affect the brain, with psychotropics sometimes referring to psychiatric drugs or high-abuse substances, while “drug” can have negative connotations. Novel psychoactive substances are designer drugs made to mimic illegal ones and bypass laws. Psychoactive drug use dates back to

prehistory Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use ...

for medicinal and consciousness-altering purposes, with evidence of widespread cultural use. Many animals intentionally consume psychoactive substances, and some traditional legends suggest animals first introduced humans to their use. Psychoactive substances are used across cultures for purposes ranging from medicinal and therapeutic treatment of

mental disorders A mental disorder, also referred to as a mental illness, a mental health condition, or a psychiatric disability, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. A mental disorder is ...

and pain, to performance enhancement. Their effects are influenced by the drug itself, the environment, and individual factors. Psychoactive drugs are categorized by their pharmacological effects into types such as

anxiolytics An anxiolytic (; also antipanic or anti-anxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxie ...

(reduce anxiety), empathogen–entactogens (enhance empathy),

stimulants Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognitio ...

(increase CNS activity),

depressants Depressants, also known as central nervous system depressants, or colloquially known as "downers", are drugs that lower neurotransmission levels, decrease the electrical activity of brain cells, or reduce arousal or stimulation in various ar ...

(decrease CNS activity), and

hallucinogens Hallucinogens, also known as psychedelics, entheogens, or historically as psychotomimetics, are a large and diverse class of psychoactive drugs that can produce altered states of consciousness characterized by major alterations in thought, mo ...

(alter perception and emotions). Psychoactive drugs are administered through various routes—including oral ingestion, injection, rectal use, and inhalation—with the method and efficiency differing by drug. Psychoactive drugs alter brain function by interacting with

neurotransmitter A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a Chemical synapse, synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell. Neurotra ...

systems—either enhancing or inhibiting activity—which can affect mood, perception, cognition, behavior, and potentially lead to dependence or long-term neural adaptations such as

sensitization Sensitization is a non-associative learning process in which repeated administration of a stimulation, stimulus results in the progressive amplification of a response. Sensitization often is characterized by an enhancement of response to a whole ...

or tolerance.

Addiction Addiction is a neuropsychological disorder characterized by a persistent and intense urge to use a drug or engage in a behavior that produces natural reward, despite substantial harm and other negative consequences. Repetitive drug use can ...

and dependence involve psychological and physical reliance on psychoactive substances, with treatments ranging from

psychotherapy Psychotherapy (also psychological therapy, talk therapy, or talking therapy) is the use of Psychology, psychological methods, particularly when based on regular Conversation, personal interaction, to help a person change behavior, increase hap ...

and

medication Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmaco ...

to emerging psychedelic therapies; global prevalence is highest for

alcohol Alcohol may refer to: Common uses * Alcohol (chemistry), a class of compounds * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcohol (drug), intoxicant found in alcoholic beverages ** Alcoholic beverage, an alco ...

cannabis ''Cannabis'' () is a genus of flowering plants in the family Cannabaceae that is widely accepted as being indigenous to and originating from the continent of Asia. However, the number of species is disputed, with as many as three species be ...

, and opioid use disorders. The legality of psychoactive drugs has long been controversial, shaped by international treaties like the 1961

Single Convention on Narcotic Drugs The Single Convention on Narcotic Drugs, 1961 (Single Convention, 1961 Convention, or C61) is an international treaty that controls activities (cultivation, production, supply, trade, transport) involving specific narcotic drugs and lays down a ...

and national laws such as the United States

Controlled Substances Act The Controlled Substances Act (CSA) is the statute establishing federal government of the United States, federal drug policy of the United States, U.S. drug policy under which the manufacture, importation, possession, use, and distribution of ...

. Distinctions are made between recreational and medical use. Enforcement varies across countries. While the 20th century saw global criminalization, recent shifts favor

harm reduction Harm reduction, or harm minimization, refers to a range of intentional practices and public health policies designed to lessen the negative social and/or physical consequences associated with various human behaviors, both legal and illegal. H ...

and regulation over prohibition. Widely used psychoactive drugs include legal substances like

caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine chemical classification, class and is the most commonly consumed Psychoactive drug, psychoactive substance globally. It is mainly used for its eugeroic (wakefulness pr ...

, and

nicotine Nicotine is a natural product, naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and ''Duboisia hopwoodii'') and is widely used recreational drug use, recreationally as a stimulant and anxiolytic. As ...

; prescribed medications such as SSRIs,

opioids Opioids are a class of Drug, drugs that derive from, or mimic, natural substances found in the Papaver somniferum, opium poppy plant. Opioids work on opioid receptors in the brain and other organs to produce a variety of morphine-like effects, ...

, and

benzodiazepines Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat co ...

; and illegal recreational drugs like

cocaine Cocaine is a tropane alkaloid and central nervous system stimulant, derived primarily from the leaves of two South American coca plants, ''Erythroxylum coca'' and ''Erythroxylum novogranatense, E. novogranatense'', which are cultivated a ...

LSD Lysergic acid diethylamide, commonly known as LSD (from German ; often referred to as acid or lucy), is a semisynthetic, hallucinogenic compound derived from ergot, known for its powerful psychological effects and serotonergic activity. I ...

, and

MDMA 3,4-Methylenedioxymethamphetamine (MDMA), commonly known as ecstasy (tablet form), and molly (crystal form), is an empathogen–entactogenic drug with stimulant and minor Psychedelic drug, psychedelic properties. In studies, it has been used ...

History

Psychoactive drug use can be traced to

. Archaeological evidence of the use of psychoactive substances, mostly plants, dates back at least 10,000 years; historical evidence indicates cultural use 5,000 years ago. There is evidence of the chewing of

coca Coca is any of the four cultivated plants in the family Erythroxylaceae, native to western South America. Coca is known worldwide for its psychoactive alkaloid, cocaine. Coca leaves contain cocaine which acts as a mild stimulant when chewed or ...

leaves, for example, in

Peruvian Peruvians (''/peruanas'') are the citizens of Peru. What is now Peru has been inhabited for several millennia by cultures such as the Caral before the Spanish conquest in the 16th century. Peruvian population decreased from an estimated 5–9 ...

society 8,000 years ago. Psychoactive substances have been used medicinally and to alter consciousness. Consciousness altering may be a primary drive, akin to the need to satiate thirst, hunger, or sexual desire. This may be manifest in the long history of drug use, and even in children's desire for spinning, swinging, or sliding, suggesting that the drive to alter one's state of mind is universal. In '' The Hasheesh Eater'' (1857), American author

Fitz Hugh Ludlow Fitz Hugh Ludlow, sometimes seen as Fitzhugh Ludlow (September 11, 1836 – September 12, 1870), was an American author, journalist, and explorer; best known for his autobiographical book ''The Hasheesh Eater'' (1857). Ludlow also wrote about hi ...

was one of the first to describe in modern terms the desire to change one's consciousness through drug use: During the 20th century, the majority of countries initially responded to the use of recreational drugs by prohibiting production, distribution, or use through criminalization. A notable example occurred with

Prohibition in the United States The Prohibition era was the period from 1920 to 1933 when the United States prohibited the production, importation, transportation, and sale of alcoholic beverages. The alcohol industry was curtailed by a succession of state legislatures, an ...

, where early in the century alcohol was made illegal for 13 years. In recent decades, an emerging perspective among governments and law enforcement holds that illicit drug use cannot be stopped through prohibition. One organization holding that view, Law Enforcement Against Prohibition (LEAP), concluded that " nfighting a war on drugs the government has increased the problems of society and made them far worse. A system of regulation rather than prohibition is a less harmful, more ethical and a more effective public policy." In some countries, there has been a move toward

, where the use of illicit drugs is neither condoned nor promoted, but services and support are provided to ensure users have adequate factual information readily available, and that the negative effects of their use be minimized. Such is the case with Portugal's drug policy of

decriminalization Decriminalization or decriminalisation is the legislative process which removes prosecutions against an action so that the action remains illegal but has no criminal penalties or at most some civil fine. This reform is sometimes applied retroacti ...

, with a primary goal of reducing the adverse health effects of drug use.

Terminology

''Psychoactive'' and ''psychotropic'' are often used interchangeably in general and academic sources, to describe substances that act on the brain to alter cognition and perception; some sources make a distinction between the terms. One narrower definition of psychotropic refers to drugs used to treat mental disorders, such as anxiolytic sedatives, antidepressants, antimanic agents, and neuroleptics. Another usage of psychotropic refers to substances determined to pose "high abuse liability", including stimulants, hallucinogens, opioids, and sedatives/hypnotics including alcohol. In international drug control, ''psychotropic substances'' refers to the substances specified in the

Convention on Psychotropic Substances The Convention on Psychotropic Substances of 1971 is a United Nations treaty designed to control psychoactive drugs such as amphetamine-type stimulants, barbiturates, benzodiazepines, and psychedelics signed in Vienna, Austria on 21 February ...

, which does not include narcotics. The term "drug" has become a

skunked term A skunked term is a word or phrase that becomes difficult to use because it is evolving from one meaning to another, perhaps inconsistent or even opposite, usage, or that becomes difficult to use due to other controversy surrounding the term. P ...

. "Drugs" can have a negative connotation, often associated with illegal substances like cocaine or heroin, despite the fact that the terms "drug" and "medicine" are sometimes used interchangeably. Novel psychoactive substances (NPS), also known as "

designer drugs A designer drug is a structural or functional analog of a controlled substance that has been designed to mimic the pharmacological effects of the original drug, while avoiding classification as illegal and/or detection in standard drug tests. ...

" are a category of psychoactive drugs (substances) that are designed to mimic the effects of often illegal drugs, usually in efforts to circumvent existing drug laws.

Types

Psychoactive drugs are divided according to their pharmacological effects. Common subtypes include: *

Anxiolytic An anxiolytic (; also antipanic or anti-anxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxie ...

s are medicinally used to reduce the symptoms of anxiety, and sometimes insomnia. ::Example:

benzodiazepine Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant, depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed t ...

s such as

Xanax Alprazolam, sold under the brand name Xanax among others, is a fast-acting, potent tranquilizer of moderate duration within the triazolobenzodiazepine group of chemicals called benzodiazepines. Alprazolam is most commonly prescribed in the ...

and Valium;

barbiturate Barbiturates are a class of depressant, depressant drugs that are chemically derived from barbituric acid. They are effective when used medication, medically as anxiolytics, hypnotics, and anticonvulsants, but have physical and psychological a ...

s * Empathogen–entactogens alter emotional state, often resulting in an increased sense of empathy, closeness, and emotional communication. ::Example:

(ecstasy), MDA, 6-APB, AMT *

Stimulant Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognition, ...

s increase activity, or arousal, of the central nervous system. They can enhance alertness, attention, cognition, mood and physical performance. Some stimulants are used medicinally to treat individuals with

ADHD Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by symptoms of inattention, hyperactivity, impulsivity, and emotional dysregulation that are excessive and pervasive, impairing in multiple ...

and

narcolepsy Narcolepsy is a chronic neurological disorder that impairs the ability to regulate sleep–wake cycles, and specifically impacts REM (rapid eye movement) sleep. The symptoms of narcolepsy include excessive daytime sleepiness (EDS), sleep-r ...

. ::Examples:

amphetamine Amphetamine (contracted from Alpha and beta carbon, alpha-methylphenethylamine, methylphenethylamine) is a central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, an ...

Depressants Depressants, also known as central nervous system depressants, or colloquially known as "downers", are drugs that lower neurotransmission levels, decrease the electrical activity of brain cells, or reduce arousal or stimulation in various ar ...

reduce, or depress, activity and stimulation in the central nervous system. This category encompasses a spectrum of substances with sedative, soporific, and anesthetic properties, and include

sedatives A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are central nervous system (CNS) depressants and interact with brain activity, causing its deceleration. Various kinds of sedatives ...

hypnotics A hypnotic (from Greek ''Hypnos'', sleep), also known as a somnifacient or soporific, and commonly known as sleeping pills, are a class of psychoactive drugs whose primary function is to induce sleep and to treat insomnia (sleeplessness). Th ...

, and

. :: Examples:

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

(alcohol), opioids such as

morphine Morphine, formerly also called morphia, is an opiate that is found naturally in opium, a dark brown resin produced by drying the latex of opium poppies (''Papaver somniferum''). It is mainly used as an analgesic (pain medication). There are ...

fentanyl Fentanyl is a highly potent synthetic piperidine opioid primarily used as an analgesic (pain medication). It is 30 to 50 times more Potency (pharmacology), potent than heroin and 50 to 100 times more potent than morphine. Its primary Medici ...

, and

codeine Codeine is an opiate and prodrug of morphine mainly used to treat pain, coughing, and diarrhea. It is also commonly used as a recreational drug. It is found naturally in the sap of the opium poppy, ''Papaver somniferum''. It is typically use ...

barbiturates Barbiturates are a class of depressant drugs that are chemically derived from barbituric acid. They are effective when used medically as anxiolytics, hypnotics, and anticonvulsants, but have physical and psychological addiction potential as ...

, and

Hallucinogens Hallucinogens, also known as psychedelics, entheogens, or historically as psychotomimetics, are a large and diverse class of psychoactive drugs that can produce altered states of consciousness characterized by major alterations in thought, mo ...

, including

psychedelics Psychedelics are a subclass of hallucinogenic drugs whose primary effect is to trigger non-ordinary mental states (known as psychedelic experiences or "trips") and a perceived "expansion of consciousness". Also referred to as classic halluci ...

, dissociatives and

deliriants Deliriants are a subclass of hallucinogen. The term was coined in the early 1980s to distinguish these drugs from psychedelics such as LSD and dissociatives such as ketamine, due to their primary effect of causing delirium, as opposed to t ...

, encompass substances that produce distinct alterations in perception, sensation of space and time, and emotional state. ::Examples, psychedelics:

Psilocybin Psilocybin, also known as 4-phosphoryloxy-''N'',''N''-dimethyltryptamine (4-PO-DMT), is a natural product, naturally occurring tryptamine alkaloid and Investigational New Drug, investigational drug found in more than List of psilocybin mushroom ...

, DMT (N,N-Dimethyltryptamine),

mescaline Mescaline, also known as mescalin or mezcalin, and in chemical terms 3,4,5-trimethoxyphenethylamine, is a natural product, naturally occurring psychedelic drug, psychedelic alkaloid, protoalkaloid of the substituted phenethylamine class, found ...

::Examples, dissociatives:

Dextromethorphan Dextromethorphan, sold under the brand name Robitussin among others, is a cough suppressant used in many cough and Common cold, cold medicines. In 2022, the US Food and Drug Administration (FDA) approved the combination dextromethorphan/bupropi ...

, '' Salvia divinorum'' ::Examples, deliriants:

Datura ''Datura'' is a genus of nine species of highly poisonous, Vespertine (biology), vespertine-flowering plants belonging to the nightshade family (Solanaceae). They are commonly known as thornapples or jimsonweeds, but are also known as devil's t ...

scopolamine Scopolamine, also known as hyoscine, or Devil's Breath, is a medication used to treat motion sickness and postoperative nausea and vomiting. It is also sometimes used before surgery to decrease saliva. When used by injection, effects begin a ...

Uses

The ways in which psychoactive substances are used vary widely between cultures. Some substances may have controlled or illegal uses, others may have shamanic purposes, and others are used medicinally. Examples would be social drinking,

nootropic Nootropics ( or ) (colloquially brain supplements, smart drugs, cognitive enhancers, memory enhancers, or brain boosters) are chemical substances which purportedly improve cognitive functions, such as attention, memory, wakefulness, and self ...

supplements, and sleep aids.

Caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine chemical classification, class and is the most commonly consumed Psychoactive drug, psychoactive substance globally. It is mainly used for its eugeroic (wakefulness pr ...

is the world's most widely consumed psychoactive substance, and is legal and unregulated in nearly all jurisdictions; in North America, 90% of adults consume caffeine daily.

Mental disorders

Psychiatric medications are psychoactive drugs prescribed for the management of mental and emotional disorders, or to aid in overcoming challenging behavior. There are six major classes of psychiatric medications: *

Antidepressants Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction. Common side effects of antidepressants include dry mouth, weight gain, dizziness, headaches, akathisia, sexu ...

treat disorders such as

clinical depression Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Intro ...

dysthymia Dysthymia ( ), known as persistent depressive disorder (PDD) in the DSM-5-TR and dysthymic disorder in ICD-11, is a psychiatric condition marked by symptoms that are similar to those of major depressive disorder, but which persist for at leas ...

anxiety Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response ...

eating disorders An eating disorder is a mental disorder defined by abnormal eating behaviors that adversely affect a person's health, physical or mental health, mental health. These behaviors may include eating too much food or too little food. Types of eatin ...

, and

borderline personality disorder Borderline personality disorder (BPD) is a personality disorder characterized by a pervasive, long-term pattern of significant interpersonal relationship instability, an acute fear of Abandonment (emotional), abandonment, and intense emotiona ...

. *

Stimulants Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognitio ...

, used to treat disorders such as

attention deficit hyperactivity disorder Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by symptoms of inattention, hyperactivity, impulsivity, and emotional dysregulation that are excessive and pervasive, impairing in multiple con ...

and

, and for weight reduction. *

Antipsychotics Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizo ...

, used to treat psychotic symptoms, such as those associated with

schizophrenia Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...

or severe

mania Mania, also known as manic syndrome, is a Psychiatry, psychiatric Abnormality (behavior), behavioral syndrome defined as a state of Abnormality (behavior), abnormally elevated arousal, affect (psychology), affect, and energy level. During a mani ...

, or as adjuncts to relieve clinical depression. *

Mood stabilizers A mood stabilizer is a psychiatric medication used to treat mood disorders characterized by intense and sustained mood shifts, such as bipolar disorder and the bipolar type of schizoaffective disorder. Uses Mood stabilizers are best known for t ...

, used to treat

bipolar disorder Bipolar disorder (BD), previously known as manic depression, is a mental disorder characterized by periods of Depression (mood), depression and periods of abnormally elevated Mood (psychology), mood that each last from days to weeks, and in ...

and

schizoaffective disorder Schizoaffective disorder is a mental disorder characterized by symptoms of both schizophrenia (psychosis) and a mood disorder, either bipolar disorder or depression. The main diagnostic criterion is the presence of psychotic symptoms for at leas ...

. *

Anxiolytics An anxiolytic (; also antipanic or anti-anxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxie ...

, used to treat

anxiety disorder Anxiety disorders are a group of mental disorders characterized by significant and uncontrollable feelings of anxiety and fear such that a person's social, occupational, and personal functions are significantly impaired. Anxiety may cause phys ...

s. *

, used as

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or Psychomotor agitation, excitement. They are central nervous system (CNS) Depressant, depressants and interact with brain activity, causing its decelera ...

s, and

anesthetic An anesthetic (American English) or anaesthetic (British English; see spelling differences) is a drug used to induce anesthesia ⁠— ⁠in other words, to result in a temporary loss of sensation or awareness. They may be divided into t ...

s, depending upon dosage. In addition, several psychoactive substances are currently employed to treat various addictions. These include

acamprosate Acamprosate, sold under the brand name Campral, is a medication which reduces cravings in alcoholism. It is thought to stabilize neurotransmission, chemical signaling in the brain that would otherwise be disrupted by alcohol withdrawal. When us ...

naltrexone Naltrexone, sold under the brand name Revia among others, is a medication primarily used to manage alcohol use or opioid use disorder by reducing cravings and feelings of euphoria associated with substance use disorder. It has also been ...

in the treatment of alcoholism, or

methadone Methadone, sold under the brand names Dolophine and Methadose among others, is a synthetic opioid used medically to treat chronic pain and opioid use disorder. Prescribed for daily use, the medicine relieves cravings and opioid withdrawal sym ...

or buprenorphine maintenance therapy in the case of opioid addiction. Exposure to psychoactive drugs can cause changes to the brain that counteract or augment some of their effects; these changes may be beneficial or harmful. However, there is a significant amount of evidence that the relapse rate of mental disorders negatively corresponds with the length of properly followed treatment regimens (that is, relapse rate substantially declines over time), and to a much greater degree than placebo.

Military

Drugs used by militaries

Militaries worldwide have used or are using various psychoactive drugs to treat pain and to improve performance of soldiers by suppressing hunger, increasing the ability to sustain effort without food, increasing and lengthening

wakefulness Wakefulness is a daily recurring brain state and state of consciousness in which an individual is conscious and engages in coherent cognition, cognitive and behavioral responses to the external world. Being awake is the opposite of being asleep, ...

and concentration, suppressing

fear Fear is an unpleasant emotion that arises in response to perception, perceived dangers or threats. Fear causes physiological and psychological changes. It may produce behavioral reactions such as mounting an aggressive response or fleeing the ...

, reducing empathy, and improving reflexes and memory-recall among other things. Both military and civilian American intelligence officials are known to have used psychoactive drugs while interrogating captives apprehended in its ''" war on terror"''. In July 2012

Jason Leopold Jason Arthur Leopold (born October 7, 1969) is an American investigative reporter who writes for ''Bloomberg News''. He was previously an investigative reporter for ''BuzzFeed, BuzzFeed News,'' ''Al Jazeera America,'' and ''Vice News''. He work ...

and Jeffrey Kaye, psychologists and human rights workers, had a Freedom of Information Act request fulfilled that confirmed that the use of psychoactive drugs during interrogation was a long-standing practice. Captives and former captives had been reporting medical staff collaborating with interrogators to drug captives with powerful psychoactive drugs prior to interrogation since the very first captives release. In May 2003 recently released Pakistani captive

Sha Mohammed Alikhel Sha Mohammed Alikhel (born 1981) is a Pakistani who was held in extrajudicial detention in the United States Guantanamo Bay detention camps, in Cuba.Jihan Wali According to the United States US Department of Defense, Department of Defense, there were five dozen Pakistani detainees in Guantanamo prior to May 15, 2006. The Guantanamo Bay detention camp was opened on January 11, 2002. In the summer of 2 ...

, a captive kept in a nearby cell, was rendered catatonic through the use of these drugs. Alcohol has a long association of military use, and has been called "

liquid courage Dutch courage, also known as pot-valiance or liquid courage, refers to courage gained from intoxication with alcohol. Uses Criminal Alcohol is occasionally used by criminals as a tool to commit alcohol-related offenses. These may include ...

" for its role in preparing troops for battle, anaesthetize injured soldiers, and celebrate military victories. It has also served as a coping mechanism for

combat stress reaction Combat stress reaction (CSR) is acute behavioral disorganization as a direct result of the trauma of war. Also known as "combat fatigue", "battle fatigue", "operational exhaustion", or "battle/war neurosis", it has some overlap with the diagnosis ...

s and a means of decompression from combat to everyday life. However, this reliance on alcohol can have negative consequences for physical and mental health. The first documented case of a soldier overdosing on

methamphetamine Methamphetamine (contracted from ) is a potent central nervous system (CNS) stimulant that is mainly used as a recreational drug use, recreational or Performance-enhancing substance, performance-enhancing drug and less commonly as a secon ...

during combat, was the Finnish corporal Aimo Koivunen, a soldier who fought in the

Winter War The Winter War was a war between the Soviet Union and Finland. It began with a Soviet invasion of Finland on 30 November 1939, three months after the outbreak of World War II, and ended three and a half months later with the Moscow Peac ...

and the

Continuation War The Continuation War, also known as the Second Soviet–Finnish War, was a conflict fought by Finland and Nazi Germany against the Soviet Union during World War II. It began with a Finnish declaration of war on 25 June 1941 and ended on 19 ...

Psychochemical warfare

Psychoactive drugs have been used in military applications as

non-lethal weapon Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be less likely to kill a living target than convention ...

Pain management

Psychoactive drugs are often prescribed to manage pain. The subjective experience of pain is primarily regulated by

endogenous Endogeny, in biology, refers to the property of originating or developing from within an organism, tissue, or cell. For example, ''endogenous substances'', and ''endogenous processes'' are those that originate within a living system (e.g. an ...

opioid peptides Opioid peptides or opiate peptides are peptides that bind to opioid receptors in the brain; opiates and opioids mimic the effect of these peptides. Such peptides may be produced by the body itself, for example endorphins. The effects of these p ...

. Thus, pain can often be managed using psychoactives that operate on this neurotransmitter system, also known as

opioid receptor agonist Opioids are a class of Drug, drugs that derive from, or mimic, natural substances found in the Papaver somniferum, opium poppy plant. Opioids work on opioid receptors in the brain and other organs to produce a variety of morphine-like effects, ...

s. This class of drugs can be highly addictive, and includes

opiate An opiate is an alkaloid substance derived from opium (or poppy straw). It differs from the similar term ''opioid'' in that the latter is used to designate all substances, both natural and synthetic, that bind to opioid receptors in the brain ( ...

narcotics The term narcotic (, from ancient Greek ναρκῶ ''narkō'', "I make numb") originally referred medically to any psychoactive compound with numbing or paralyzing properties. In the United States, it has since become associated with opiates ...

, like

and

NSAID Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...

s, such as

aspirin Aspirin () is the genericized trademark for acetylsalicylic acid (ASA), a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and inflammation, and as an antithrombotic. Specific inflammatory conditions that aspirin is ...

and

ibuprofen Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that is used to relieve pain, fever, and inflammation. This includes dysmenorrhea, painful menstrual periods, migraines, and rheumatoid arthritis. It can be taken oral administration, ...

, are also analgesics. These agents also reduce

eicosanoid Eicosanoids are lipid signaling, signaling molecules made by the enzymatic or non-enzymatic oxidation of arachidonic acid or other polyunsaturated fatty acids (PUFAs) that are, similar to arachidonic acid, around 20 carbon units in length. Eicosa ...

-mediated

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

by inhibiting the enzyme

cyclooxygenase Cyclooxygenase (COX), officially known as prostaglandin-endoperoxide synthase (PTGS), is an enzyme (specifically, a family of isozymes, ) that is responsible for biosynthesis of prostanoids, including thromboxane and prostaglandins such a ...

Anesthesia

General anesthetics General anaesthetics (or anesthetics) are often defined as compounds that induce a loss of consciousness in humans or loss of righting reflex in animals. Clinical definitions are also extended to include an induced coma that causes lack of aware ...

are a class of psychoactive drug used on people to block physical pain and other sensations. Most anesthetics induce

unconsciousness Unconsciousness is a state in which a living individual exhibits a complete, or near-complete, inability to maintain an awareness of self and environment or to respond to any human or environmental stimulus. Unconsciousness may occur as the r ...

, allowing the person to undergo medical procedures like

surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

, without the feelings of physical pain or emotional trauma. To induce unconsciousness, anesthetics affect the

GABA GABA (gamma-aminobutyric acid, γ-aminobutyric acid) is the chief inhibitory neurotransmitter in the developmentally mature mammalian central nervous system. Its principal role is reducing neuronal excitability throughout the nervous system. GA ...

and

NMDA ''N''-methyl--aspartic acid, or ''N''-methyl--aspartate (NMDA), is an amino acid derivative that acts as a specific agonist at the NMDA receptor mimicking the action of glutamate, the neurotransmitter which normally acts at that receptor. Unl ...

systems. For example,

Propofol Propofol is the active component of an intravenous anesthetic formulation used for induction and maintenance of general anesthesia. It is chemically termed 2,6-diisopropylphenol. The formulation was approved under the brand name Diprivan. Nu ...

is a GABA agonist, and

ketamine Ketamine is a cyclohexanone-derived general anesthetic and NMDA receptor antagonist with analgesic and hallucinogenic properties, used medically for anesthesia, depression, and pain management. Ketamine exists as its S- (esketamine) a ...

is an

NMDA receptor antagonist NMDA receptor antagonists are a class of drugs that work to receptor antagonist, antagonize, or inhibit the action of, the NMDA, ''N''-Methyl-D-aspartate receptor (NMDA receptor, NMDAR). They are commonly used as anesthetics for humans and anima ...

Performance-enhancement

Performance-enhancing substance Performance-enhancing substances (PESs), also known as performance-enhancing drugs (PEDs), are substances that are used to improve any form of activity performance in humans. Many substances, such as anabolic steroids, can be used to improve ath ...

s, also known as performance-enhancing drugs (PEDs), are substances that are used to improve any form of activity performance in humans. A well-known example of

cheating in sports Cheating in sports may refer to: * Age fraud in association football * Cheating * Cheating at the Olympic Games * Cheating at the Paralympic Games * Cheating in baseball Baseball personnel have cheated by deliberately violating or circumventi ...

involves

doping in sport In competitive sports, doping is the use of banned athletic performance-enhancing drugs (PEDs) by athletes, as a way of cheating. As stated in the World Anti-Doping Code by WADA, doping is defined as the occurrence of one or more of the anti-d ...

, where banned physical performance-enhancing drugs are used by athletes and bodybuilders. Athletic performance-enhancing substances are sometimes referred as ergogenic aids. Cognitive performance-enhancing drugs, commonly called

nootropics Nootropics ( or ) (colloquially brain supplements, smart drugs, cognitive enhancers, memory enhancers, or brain boosters) are chemical substances which purportedly improve cognitive functions, such as attention, memory, wakefulness, and self- ...

, are sometimes used by students to improve academic performance. Performance-enhancing substances are also used by military personnel to enhance combat performance.

Recreation

Many psychoactive substances are used for their mood and perception altering effects, including those with accepted uses in medicine and psychiatry. Examples of psychoactive substances include

, and

dextromethorphan Dextromethorphan, sold under the brand name Robitussin among others, is a cough suppressant used in many cough and Common cold, cold medicines. In 2022, the US Food and Drug Administration (FDA) approved the combination dextromethorphan/bupropi ...

.Neuroscience of Psychoactive Substance Use and Dependence
by 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 ...

. Retrieved 5 July 2007. Classes of drugs frequently used recreationally include: *

, which activate the

. These are used recreationally for their

euphoric Euphoria ( ) is the experience (or affect) of pleasure or excitement and intense feelings of well-being and happiness. Certain natural rewards and social activities, such as aerobic exercise, laughter, listening to or making music and danci ...

effects. *

(

, dissociatives and

), which induce perceptual and cognitive alterations. *

Hypnotics A hypnotic (from Greek ''Hypnos'', sleep), also known as a somnifacient or soporific, and commonly known as sleeping pills, are a class of psychoactive drugs whose primary function is to induce sleep and to treat insomnia (sleeplessness). Th ...

, which depress the central nervous system. * Opioid analgesics, which also depress the central nervous system. These are used recreationally because of their euphoric effects. * Inhalants, in the forms of gas aerosols, or solvents, which are inhaled as a vapor because of their stupefying effects. Many inhalants also fall into the above categories (such as

nitrous oxide Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or factitious air, among others, is a chemical compound, an Nitrogen oxide, oxide of nitrogen with the Chemical formula, formula . At room te ...

which is also an analgesic). In some modern and ancient cultures, drug usage is seen as a

status Status (Latin plural: ''statūs''), is a state, condition, or situation, and may refer to: * Status (law) ** Legal status, in law ** Political status, in international law ** Small entity status, in patent law ** Status conference ** Status c ...

symbol. Recreational drugs are seen as status symbols in settings such as at

nightclub A nightclub or dance club is a club that is open at night, usually for drinking, dancing and other entertainment. Nightclubs often have a Bar (establishment), bar and discotheque (usually simply known as disco) with a dance floor, laser lighti ...

s and parties. For example, in

ancient Egypt Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower E ...

, gods were commonly pictured holding hallucinogenic plants. Because there is controversy about regulation of recreational drugs, there is an ongoing debate about drug prohibition. Critics of prohibition believe that regulation of recreational drug use is a violation of personal autonomy and

freedom Freedom is the power or right to speak, act, and change as one wants without hindrance or restraint. Freedom is often associated with liberty and autonomy in the sense of "giving oneself one's own laws". In one definition, something is "free" i ...

. In the United States, critics have noted that prohibition or regulation of recreational and spiritual drug use might be

unconstitutional In constitutional law, constitutionality is said to be the condition of acting in accordance with an applicable constitution; "Webster On Line" the status of a law, a procedure, or an act's accordance with the laws or set forth in the applic ...

, and causing more harm than is prevented. Some people who take psychoactive drugs experience drug or substance induced psychosis. A 2019 systematic review and meta-analysis by Murrie et al. found that the pooled proportion of transition from substance-induced psychosis to schizophrenia was 25% (95% CI 18%–35%), compared with 36% (95% CI 30%–43%) for brief, atypical and not otherwise specified psychoses. Type of substance was the primary predictor of transition from drug-induced psychosis to schizophrenia, with highest rates associated with cannabis (6 studies, 34%, CI 25%–46%), hallucinogens (3 studies, 26%, CI 14%–43%) and amphetamines (5 studies, 22%, CI 14%–34%). Lower rates were reported for opioid (12%), alcohol (10%) and sedative (9%) induced psychoses. Transition rates were slightly lower in older cohorts but were not affected by sex, country of the study, hospital or community location, urban or rural setting, diagnostic methods, or duration of follow-up.

Ritual and spiritual

Offerings

Alcohol and tobacco (nicotine) have been and are used as offerings in various religions and spiritual practices. Coca leaves have been used as offerings in rituals.

=Alcohol

= According to the

Catholic Church The Catholic Church (), also known as the Roman Catholic Church, is the List of Christian denominations by number of members, largest Christian church, with 1.27 to 1.41 billion baptized Catholics Catholic Church by country, worldwid ...

, the sacramental wine used in the Eucharist must contain alcohol. Canon 924 of the present Code of Canon Law (1983) states:

§3 The wine must be natural, made from grapes of the vine, and not corrupt.

Psychoactive use

=Entheogen

Certain psychoactives, particularly hallucinogens, have been used for religious purposes since prehistoric times. Native Americans have used

peyote The peyote (; ''Lophophora williamsii'' ) is a small, spineless cactus which contains psychoactive alkaloids, particularly mescaline. is a Spanish word derived from the Nahuatl (), meaning "caterpillar cocoon", from a root , "to glisten". p. ...

cacti containing

for religious ceremonies for as long as 5700 years. The muscimol-containing ''

Amanita muscaria ''Amanita muscaria'', commonly known as the fly agaric or fly amanita, is a basidiomycete fungus of the genus ''Amanita''. It is a large white-lamella (mycology), gilled, white-spotted mushroom typically featuring a bright red cap covered with ...

'' mushroom was used for ritual purposes throughout prehistoric Europe. The use of entheogens for religious purposes resurfaced in the West during the counterculture movements of the 1960s and 70s. Under the leadership of

Timothy Leary Timothy Francis Leary (October 22, 1920 – May 31, 1996) was an American psychologist and author known for his strong advocacy of psychedelic drugs. Evaluations of Leary are polarized, ranging from "bold oracle" to "publicity hound". Accordin ...

, new spiritual and intention-based movements began to use

and other hallucinogens as tools to access deeper inner exploration. In the United States, the use of peyote for ritual purposes is protected only for members of the

Native American Church The Native American Church (NAC), also known as Peyotism and Peyote Religion, is a Syncretism, syncretic Native American religion that teaches a combination of traditional Native Americans in the United States, Native American beliefs and eleme ...

, which is allowed to cultivate and distribute

. However, the genuine religious use of peyote, regardless of one's personal ancestry, is protected in Colorado, Arizona, New Mexico, Nevada, and Oregon.

=Psychedelic therapy

= Psychedelic therapy (or psychedelic-assisted therapy) refers to the proposed use of

psychedelic drug Psychedelics are a subclass of hallucinogenic drugs whose primary effect is to trigger non-ordinary mental states (known as psychedelic experiences or "trips") and a perceived "expansion of consciousness". Also referred to as classic halluc ...

s, such as

psilocybin Psilocybin, also known as 4-phosphoryloxy-''N'',''N''-dimethyltryptamine (4-PO-DMT), is a natural product, naturally occurring tryptamine alkaloid and Investigational New Drug, investigational drug found in more than List of psilocybin mushroom ...

, and

ayahuasca AyahuascaPronounced as in the UK and in the US. Also occasionally known in English as ''ayaguasca'' (Spanish-derived), ''aioasca'' (Brazilian Portuguese-derived), or as ''yagé'', pronounced or . Etymologically, all forms but ''yagé'' descen ...

, to treat

mental disorder A mental disorder, also referred to as a mental illness, a mental health condition, or a psychiatric disability, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. A mental disorder is ...

s. As of 2021, psychedelic drugs are controlled substances in most countries and psychedelic therapy is not legally available outside clinical trials, with some exceptions.

=Psychonautics

= The aims and methods of psychonautics, when state-altering substances are involved, is commonly distinguished from

recreational drug use Recreational drug use is the use of one or more psychoactive drugs to induce an altered state of consciousness, either for pleasure or for some other casual purpose or pastime. When a psychoactive drug enters the user's body, it induces an Sub ...

by research sources. Psychonautics as a means of exploration need not involve drugs, and may take place in a religious context with an established history. Cohen considers psychonautics closer in association to wisdom traditions and other transpersonal and integral movements.UK Institute of Psychonautics and Somanautic
page
at his

Self-medication

Self-medication Self-medication, sometime called do-it-yourself (DIY) medicine, is a human behavior in which an individual uses a substance or any exogenous influence to self-administer treatment for physical or psychological conditions, for example headaches or ...

, sometime called do-it-yourself (DIY) medicine, is a

human behavior Human behavior is the potential and expressed capacity (Energy (psychological), mentally, Physical activity, physically, and Social action, socially) of human individuals or groups to respond to internal and external Stimulation, stimuli throu ...

in which an individual uses a substance or any exogenous influence to self-administer treatment for physical or psychological conditions, for example

headache A headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of Depression (mood), depression in those with severe ...

s or

fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

. The substances most widely used in self-medication are

over-the-counter Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a requirement for a prescription from a healthcare professional, as opposed to prescription drugs, which may be supplied only to consumers possessing a valid pres ...

drugs and dietary supplements, which are used to treat common health issues at home. These do not require a doctor's prescription to obtain and, in some countries, are available in supermarkets and convenience stores.

Sex

Sex Sex is the biological trait that determines whether a sexually reproducing organism produces male or female gametes. During sexual reproduction, a male and a female gamete fuse to form a zygote, which develops into an offspring that inheri ...

and

drugs A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via inhalation, injection, smoking, ingestio ...

date back to ancient humans and have been interlocked throughout human history. Both legal and illegal, the consumption of

drug A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...

s and their effects on the human body encompasses all aspects of sex, including

desire Desires are states of mind that are expressed by terms like "wanting", "wishing", "longing" or "craving". A great variety of features is commonly associated with desires. They are seen as propositional attitudes towards conceivable states of affa ...

performance A performance is an act or process of staging or presenting a play, concert, or other form of entertainment. It is also defined as the action or process of carrying out or accomplishing an action, task, or function. Performance has evolved glo ...

pleasure Pleasure is experience that feels good, that involves the enjoyment of something. It contrasts with pain or suffering, which are forms of feeling bad. It is closely related to value, desire and action: humans and other conscious animals find ...

, conception,

gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...

, and

disease A disease is a particular abnormal condition that adversely affects the structure or function (biology), function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical condi ...

. There are many different types of drugs that are commonly associated with their effects on sex, including

, GHB,

amphetamines Substituted amphetamines, or simply amphetamines, are a chemical class, class of compounds based upon the amphetamine structure; it includes all derivative (chemistry), derivative compounds which are formed by replacing, or substitution reacti ...

opioid Opioids are a class of Drug, drugs that derive from, or mimic, natural substances found in the Papaver somniferum, opium poppy plant. Opioids work on opioid receptors in the brain and other organs to produce a variety of morphine-like effects, ...

antidepressant Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction. Common side effects of antidepressants include Xerostomia, dry mouth, weight gain, dizziness, headaches, akathi ...

s, and many others.

Social movements

Cannabis

In the US, NORML (

National Organization for the Reform of Marijuana Laws The National Organization for the Reform of Marijuana Laws (NORML ) is a social welfare organization based in Washington, D.C., that advocates for the reform of marijuana laws in the United States regarding both Medical cannabis in the United St ...

) has led since the 1970s a movement to legalize cannabis nationally.Joshua Clark Davis. (November 6, 2014)
The Long Marijuana-Rights Movement.
The Huffington Post. Retrieved August 3, 2016. The so-called " 420 movement" is the global association of the number 420 with cannabis consumption: April 20th – fourth month, twentieth day – has become an international

counterculture A counterculture is a culture whose values and norms of behavior differ substantially from those of mainstream society, sometimes diametrically opposed to mainstream cultural mores.Eric Donald Hirsch. ''The Dictionary of Cultural Literacy''. Ho ...

holiday A holiday is a day or other period of time set aside for festivals or recreation. ''Public holidays'' are set by public authorities and vary by state or region. Religious holidays are set by religious organisations for their members and are often ...

based on the celebration and consumption of cannabis; 4:20 pm on any day is a time to consume cannabis.

=Operation Overgrow

= Operation Overgrow is the name, given by

activists, of an "operation" to spread marijuana seeds wildly "so it grows like weed". The thought behind the operation is to draw attention to the debate about legalization/decriminalization of marijuana.

Suicide

drug overdose A drug overdose (overdose or OD) is the ingestion or application of a drug or other substance in quantities much greater than are recommended. Retrieved on September 20, 2014.

involves taking a dose of a

that exceeds safe levels. In the UK (England and Wales) until 2013, a drug overdose was the most common suicide method in females. In 2019 in males the percentage is 16%. Self-poisoning accounts for the highest number of non-fatal suicide attempts. In the United States about 60% of suicide attempts and 14% of suicide deaths involve drug overdoses. The risk of death in suicide attempts involving overdose is about 2%. Most people are under the influence of sedative-hypnotic drugs (such as

or benzodiazepines) when they die by suicide, with alcoholism present in between 15% and 61% of cases. Countries that have higher rates of alcohol use and a greater density of bars generally also have higher rates of suicide. About 2.2–3.4% of those who have been treated for alcoholism at some point in their life die by suicide. Alcoholics who attempt suicide are usually male, older, and have tried to take their own lives in the past. In adolescents who misuse alcohol, neurological and psychological dysfunctions may contribute to the increased risk of suicide. Overdose attempts using painkillers are among the most common, due to their easy availability over-the-counter.

Route of administration

Psychoactive drugs are administered via oral

ingestion Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in a substance through the mouth into the gastrointestinal tract, such as through eating or drinking. In single-celled organisms, inge ...

as a tablet, capsule, powder, liquid, and beverage; via

injection Injection or injected may refer to: Science and technology * Injective function, a mathematical function mapping distinct arguments to distinct values * Injection (medicine), insertion of liquid into the body with a syringe * Injection, in broadca ...

by subcutaneous,

intramuscular Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles hav ...

, and

intravenous Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutr ...

route; via rectum by

suppository A suppository is a dosage form used to deliver pharmaceutical drug, medications by insertion into a body orifice (any opening in the body), where it dissolves or melts to exert local or systemic effects. There are three types of suppositories, eac ...

and

enema An enema, also known as a clyster, is the rectal administration of a fluid by injection into the Large intestine, lower bowel via the anus.Cullingworth, ''A Manual of Nursing, Medical and Surgical'':155 The word ''enema'' can also refer to the ...

; and via inhalation by

smoking Smoking is a practice in which a substance is combusted, and the resulting smoke is typically inhaled to be tasted and absorbed into the bloodstream of a person. Most commonly, the substance used is the dried leaves of the tobacco plant, whi ...

, vaporizing, and snorting. The efficiency of each method of administration varies from drug to drug. The psychiatric drugs

fluoxetine Fluoxetine, sold under the brand name Prozac, among others, is an Antidepressant, antidepressant medication of the selective serotonin reuptake inhibitor (SSRI) class used for the treatment of major depressive disorder, Anxiety disorder, anx ...

, quetiapine, and

lorazepam Lorazepam, sold under the brand name Ativan, Tavor among others, is a benzodiazepine medication. It is used to treat anxiety (including anxiety disorders), insomnia, severe agitation, active seizures including status epilepticus, alcoh ...

are

ingest Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in a substance through the mouth into the gastrointestinal tract, such as through eating or drinking. In single-celled organisms, inges ...

ed orally in tablet or capsule form.

Alcohol Alcohol may refer to: Common uses * Alcohol (chemistry), a class of compounds * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcohol (drug), intoxicant found in alcoholic beverages ** Alcoholic beverage, an alco ...

and

are ingested in beverage form;

and

are smoked or vaporized;

and

psilocybin mushroom Psilocybin mushrooms, or psilocybin-containing mushrooms, commonly known as magic mushrooms or as shrooms, are a type of hallucinogenic mushroom and a polyphyletic informal group of fungi that contain the prodrug psilocybin, which turns into t ...

s are ingested in botanical form or dried; and crystalline drugs such as

and

are usually inhaled or snorted.

Determinants of effects

The theory of dosage, set, and setting is a useful model in dealing with the effects of psychoactive substances, especially in a controlled therapeutic setting as well as in recreational use. Dr. Timothy Leary, based on his own experiences and systematic observations on psychedelics, developed this theory along with his colleagues Ralph Metzner, and Richard Alpert (

Ram Dass Ram Dass (born Richard Alpert; April 6, 1931 – December 22, 2019), also known as Baba Ram Dass, was an American spiritual teacher, guru of modern yoga, psychologist, and writer. His best-selling 1971 book '' Be Here Now'', which has been d ...

) in the 1960s. ; Dosage The first factor, dosage, has been a truism since ancient times, or at least since

Paracelsus Paracelsus (; ; 1493 – 24 September 1541), born Theophrastus von Hohenheim (full name Philippus Aureolus Theophrastus Bombastus von Hohenheim), was a Swiss physician, alchemist, lay theologian, and philosopher of the German Renaissance. H ...

who said, "Dose makes the poison." Some compounds are beneficial or pleasurable when consumed in small amounts, but harmful, deadly, or evoke discomfort in higher doses. ; Set The set is the internal attitudes and constitution of the person, including their expectations, wishes, fears, and sensitivity to the drug. This factor is especially important for the hallucinogens, which have the ability to make conscious experiences out of the unconscious. In traditional cultures, set is shaped primarily by the worldview, health and genetic characteristics that all the members of the culture share. ; Setting The third aspect is setting, which pertains to the surroundings, the place, and the time in which the experiences transpire. This theory clearly states that the effects are equally the result of chemical, pharmacological, psychological, and physical influences. The model that Timothy Leary proposed applied to the psychedelics, although it also applies to other psychoactives.

Effects

Psychoactive drugs operate by temporarily affecting a person's

neurochemistry Neurochemistry is the study of chemicals, including neurotransmitters and other molecules such as psychopharmaceuticals and neuropeptides, that control and influence the physiology of the nervous system. This particular field within neuroscience e ...

, which in turn causes changes in a person's mood, cognition, perception and behavior. There are many ways in which psychoactive drugs can affect the brain. Each drug has a specific action on one or more

neuroreceptor A neurotransmitter receptor (also known as a neuroreceptor) is a membrane receptor protein that is activated by a neurotransmitter. Chemicals on the outside of the cell, such as a neurotransmitter, can bump into the cell's membrane, in which the ...

in the brain. Drugs that increase activity in particular neurotransmitter systems are called

agonists An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the agon ...

. They act by increasing the

synthesis Synthesis or synthesize may refer to: Science Chemistry and biochemistry *Chemical synthesis, the execution of chemical reactions to form a more complex molecule from chemical precursors **Organic synthesis, the chemical synthesis of organi ...

of one or more neurotransmitters, by reducing its

reuptake Reuptake is the reabsorption of a neurotransmitter by a neurotransmitter transporter located along the plasma membrane of an axon terminal (i.e., the pre-synaptic neuron at a synapse) or glial cell after it has performed its function of transmi ...

from the

synapses In the nervous system, a synapse is a structure that allows a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or a target effector cell. Synapses can be classified as either chemical or electrical, depending o ...

, or by mimicking the action by binding directly to the postsynaptic receptor. Drugs that reduce neurotransmitter activity are called

antagonists An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.neurons A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

, as the nervous system tries to re-establish the

homeostasis In biology, homeostasis (British English, British also homoeostasis; ) is the state of steady internal physics, physical and chemistry, chemical conditions maintained by organism, living systems. This is the condition of optimal functioning fo ...

disrupted by the presence of the drug (see also,

neuroplasticity Neuroplasticity, also known as neural plasticity or just plasticity, is the ability of neural networks in the brain to change through neurogenesis, growth and reorganization. Neuroplasticity refers to the brain's ability to reorganize and rewir ...

). Exposure to antagonists for a particular neurotransmitter can increase the number of receptors for that neurotransmitter or the receptors themselves may become more responsive to neurotransmitters; this is called

. Conversely, overstimulation of receptors for a particular neurotransmitter may cause a decrease in both number and sensitivity of these receptors, a process called desensitization or tolerance. Sensitization and desensitization are more likely to occur with long-term exposure, although they may occur after only a single exposure. These processes are thought to play a role in drug dependence and addiction.

Physical dependence Physical dependence is a physical condition caused by chronic use of a tolerance-forming drug, in which abrupt or gradual drug withdrawal causes unpleasant physical symptoms. Physical dependence can develop from low-dose therapeutic use of certa ...

on antidepressants or anxiolytics may result in worse depression or anxiety, respectively, as withdrawal symptoms. Unfortunately, because

(also called

major depressive disorder Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive depression (mood), low mood, low self-esteem, and anhedonia, loss of interest or pleasure in normally ...

) is often referred to simply as depression, antidepressants are often requested by and prescribed for patients who are depressed, but not clinically depressed.

Affected neurotransmitter systems

The following is a brief table of notable drugs and their primary neurotransmitter, receptor or method of action. Many drugs act on more than one transmitter or receptor in the brain.

Addiction and dependence

Psychoactive drugs are often associated with

addiction Addiction is a neuropsychological disorder characterized by a persistent and intense urge to use a drug or engage in a behavior that produces natural reward, despite substantial harm and other negative consequences. Repetitive drug use can ...

drug dependence Substance dependence, also known as drug dependence, is a biopsychological situation whereby an individual's functionality is dependent on the necessitated re-consumption of a psychoactive substance because of an adaptive state that has develope ...

. Dependence can be divided into two types:

psychological dependence Psychological dependence is a cognitive disorder and a form of dependence that is characterized by emotional–motivational withdrawal symptoms upon cessation of prolonged drug use or certain repetitive behaviors. Consistent and frequent expos ...

, by which a user experiences negative psychological or emotional withdrawal symptoms (e.g., depression) and

physical dependence Physical dependence is a physical condition caused by chronic use of a tolerance-forming drug, in which abrupt or gradual drug withdrawal causes unpleasant physical symptoms. Physical dependence can develop from low-dose therapeutic use of certa ...

, by which a user must use a drug to avoid physically uncomfortable or even medically harmful physical withdrawal symptoms. Drugs that are both rewarding and reinforcing are addictive; these properties of a drug are mediated through activation of the mesolimbic dopamine pathway, particularly the

nucleus accumbens The nucleus accumbens (NAc or NAcc; also known as the accumbens nucleus, or formerly as the ''nucleus accumbens septi'', Latin for ' nucleus adjacent to the septum') is a region in the basal forebrain rostral to the preoptic area of the hypo ...

. Not all addictive drugs are associated with physical dependence, e.g.,

, and not all drugs that produce physical dependence are addictive drugs, e.g.,

oxymetazoline Oxymetazoline, sold under the brand name Afrin among others, is a topical decongestant and vasoconstrictor medication. It is available over-the-counter as a nasal spray to treat nasal congestion and nosebleeds, as eye drops to treat eye rednes ...

. Globally, as of 2016,

alcohol use disorder Alcoholism is the continued drinking of alcohol despite it causing problems. Some definitions require evidence of dependence and withdrawal. Problematic use of alcohol has been mentioned in the earliest historical records. The World Hea ...

s were the most prevalent of all substance use disorders (SUD) worldwide; cannabis dependence and opioid dependence were the next most prevalent SUDs. Many professionals, self-help groups, and businesses specialize in

drug rehabilitation Drug rehabilitation is the process of medical or psychotherapeutic treatment for dependency on psychoactive substances such as alcohol, prescription drugs, and street drugs such as cannabis, cocaine, heroin, and amphetamines. The general int ...

, with varying degrees of success, and many parents attempt to influence the actions and choices of their children regarding psychoactives. Common forms of rehabilitation include

support groups In a support group, members provide each other with various types of help, usually nonprofessional and nonmaterial, for a particular shared, usually burdensome, characteristic. Members with the same issues can come together for sharing coping str ...

and

pharmacotherapy Pharmacotherapy, also known as pharmacological therapy or drug therapy, is defined as medical treatment that utilizes one or more pharmaceutical drugs to improve ongoing symptoms (symptomatic relief), treat the underlying condition, or act as a p ...

, which uses psychoactive substances to reduce cravings and physiological withdrawal symptoms while a user is going through detox.

Methadone Methadone, sold under the brand names Dolophine and Methadose among others, is a synthetic opioid used medically to treat chronic pain and opioid use disorder. Prescribed for daily use, the medicine relieves cravings and opioid withdrawal sym ...

, itself an

and a psychoactive substance, is a common treatment for

heroin Heroin, also known as diacetylmorphine and diamorphine among other names, is a morphinan opioid substance synthesized from the Opium, dried latex of the Papaver somniferum, opium poppy; it is mainly used as a recreational drug for its eupho ...

addiction, as is another opioid, buprenorphine. Recent research on addiction has shown some promise in using

such as

ibogaine Ibogaine is a psychoactive indole alkaloid derived from plants such as '' Tabernanthe iboga'', characterized by hallucinogenic and oneirogenic effects. Traditionally used by Central African foragers, it has undergone controversial research ...

to treat and even cure

drug addiction Addiction is a neuropsychological disorder characterized by a persistent and intense urge to use a drug or engage in a behavior that produces natural reward, despite substantial harm and other negative consequences. Repetitive drug use can ...

s, although this has yet to become a widely accepted practice.

Legality

The legality of psychoactive drugs has been controversial through most of ''recent'' history; the

Second Opium War The Second Opium War (), also known as the Second Anglo-Chinese War or ''Arrow'' War, was fought between the United Kingdom, France, Russia, and the United States against the Qing dynasty of China between 1856 and 1860. It was the second major ...

and

Prohibition Prohibition is the act or practice of forbidding something by law; more particularly the term refers to the banning of the manufacture, storage (whether in barrels or in bottles), transportation, sale, possession, and consumption of alcoholic b ...

are two historical examples of legal controversy surrounding psychoactive drugs. However, in recent years, the most influential document regarding the legality of psychoactive drugs is the

, an international

treaty A treaty is a formal, legally binding written agreement between sovereign states and/or international organizations that is governed by international law. A treaty may also be known as an international agreement, protocol, covenant, convention ...

signed in 1961 as an Act of the

United Nations The United Nations (UN) is the Earth, global intergovernmental organization established by the signing of the Charter of the United Nations, UN Charter on 26 June 1945 with the stated purpose of maintaining international peace and internationa ...

. Signed by 73 nations including the United States, the

USSR The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

, Pakistan, India, and the United Kingdom, the Single Convention on Narcotic Drugs established Schedules for the legality of each drug and laid out an international agreement to fight addiction to

recreational drugs Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or plea ...

by combatting the sale, trafficking, and use of scheduled drugs.United Nations Single Convention on Narcotic Drugs.
Retrieved on June 20, 2007. All countries that signed the treaty passed laws to implement these rules within their borders. However, some countries that signed the Single Convention on Narcotic Drugs, such as the Netherlands, are more lenient with their enforcement of these laws. In the United States, the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

(FDA) has authority over all drugs, including psychoactive drugs. The FDA regulates which psychoactive drugs are

over the counter Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a requirement for a prescription from a healthcare professional, as opposed to prescription drugs, which may be supplied only to consumers possessing a valid pres ...

and which are only available with a prescription. However, certain psychoactive drugs, like alcohol, tobacco, and drugs listed in the Single Convention on Narcotic Drugs are subject to criminal laws. The

of 1970 regulates the recreational drugs outlined in the Single Convention on Narcotic Drugs. Alcohol is regulated by state governments, but the federal

National Minimum Drinking Age Act The National Minimum Drinking Age Act of 1984 () was passed by the United States Congress and was later signed into law by President Ronald Reagan on July 17, 1984. The act punished any state that allowed persons under 21 years to purchase alco ...

penalizes states for not following a national drinking age. Tobacco is also regulated by all fifty state governments. Most people accept such restrictions and prohibitions of certain drugs, especially the "hard" drugs, which are illegal in most countries. In the medical context, psychoactive drugs as a treatment for illness is widespread and generally accepted. Little controversy exists concerning

psychoactive medications in antiemetics and antitussives. Psychoactive drugs are commonly prescribed to patients with psychiatric disorders. However, certain critics believe that certain prescription psychoactives, such as

antidepressants Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction. Common side effects of antidepressants include dry mouth, weight gain, dizziness, headaches, akathisia, sexu ...

and

, are overprescribed and threaten patients' judgement and autonomy.

Effect on animals

A number of animals consume different psychoactive plants, animals, berries and even fermented fruit, becoming intoxicated. An example of this is cats after consuming

catnip ''Nepeta cataria'', commonly known as catnip and catmint, is a species of the genus ''Nepeta'' in the mint family, native plant, native to southern and eastern Europe, northern parts of the Middle East, and Central Asia. It is widely naturalis ...

. Traditional legends of sacred plants often contain references to animals that introduced humankind to their use. Animals and psychoactive plants appear to have co-evolved, possibly explaining why these chemicals and their receptors exist within the nervous system.

Widely used psychoactive drugs

This is a list of commonly used drugs that contain psychoactive ingredients. Please note that the following lists contains legal and illegal drugs (based on the country's laws).

Common legal drugs

The most widely consumed psychotropic drugs worldwide are: *

Nicotine Nicotine is a natural product, naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and ''Duboisia hopwoodii'') and is widely used recreational drug use, recreationally as a stimulant and anxiolytic. As ...

Common prescribed drugs

Benzodiazepine Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant, depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed t ...

s *

Cannabis ''Cannabis'' () is a genus of flowering plants in the family Cannabaceae that is widely accepted as being indigenous to and originating from the continent of Asia. However, the number of species is disputed, with as many as three species be ...

Opioid Opioids are a class of Drug, drugs that derive from, or mimic, natural substances found in the Papaver somniferum, opium poppy plant. Opioids work on opioid receptors in the brain and other organs to produce a variety of morphine-like effects, ...

s *

Amphetamines Substituted amphetamines, or simply amphetamines, are a chemical class, class of compounds based upon the amphetamine structure; it includes all derivative (chemistry), derivative compounds which are formed by replacing, or substitution reacti ...

SSRI Selective serotonin reuptake inhibitors (SSRIs) are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder, anxiety disorders, and other psychological conditions. SSRIs primarily work by ...

Common street drugs

Cocaine Cocaine is a tropane alkaloid and central nervous system stimulant, derived primarily from the leaves of two South American coca plants, ''Erythroxylum coca'' and ''Erythroxylum novogranatense, E. novogranatense'', which are cultivated a ...

Heroin Heroin, also known as diacetylmorphine and diamorphine among other names, is a morphinan opioid substance synthesized from the Opium, dried latex of the Papaver somniferum, opium poppy; it is mainly used as a recreational drug for its eupho ...

Methamphetamine Methamphetamine (contracted from ) is a potent central nervous system (CNS) stimulant that is mainly used as a recreational drug use, recreational or Performance-enhancing substance, performance-enhancing drug and less commonly as a secon ...

* Ecstasy *

Psilocybin mushroom Psilocybin mushrooms, or psilocybin-containing mushrooms, commonly known as magic mushrooms or as shrooms, are a type of hallucinogenic mushroom and a polyphyletic informal group of fungi that contain the prodrug psilocybin, which turns into t ...

s *

Pharmaceutical drug Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the ...

s *

Notes

References

External links

Neuroscience of Psychoactive Substance Use and Dependence
by the

WHO The World Health Organization (WHO) is a specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Geneva, Switzerland, and has 6 regional offices and 15 ...

{{Authority control fi:Psykoaktiivinen aine

History

Terminology

Types

Uses

Mental disorders

Military

Drugs used by militaries

Psychochemical warfare

Pain management

Anesthesia

Performance-enhancement

Recreation

Ritual and spiritual

Offerings

=Alcohol

Psychoactive use

=Entheogen

=Psychedelic therapy

=Psychonautics

Self-medication

Sex

Social movements

Cannabis

=Operation Overgrow

Suicide

Route of administration

Determinants of effects

Effects

Affected neurotransmitter systems

Addiction and dependence

Legality

Effect on animals

Widely used psychoactive drugs

Common legal drugs

Common prescribed drugs

Common street drugs

See also

Notes

References

External links