Caffeine-induced Psychosis

Caffeine-induced psychosis is a relatively rare phenomenon characterized by psychotic symptoms such as delusions, paranoia, and hallucinations, and which can occur in otherwise healthy people. Overuse of caffeine may also worsen psychosis in people suffering from schizophrenia. This can happen with ingestion of high doses of caffeine, or when caffeine is chronically abused. However, there is a limited amount of evidence that confirms this.

Psychosis refers to a collection of symptoms that affect the mind, where there has been some loss of contact with reality. During an episode of psychosis, a person's thoughts and perceptions are disrupted and they may have difficulty recognizing what is real and what is not. This state of mind may be caused by a range of mental illnesses (schizophrenia, bipolar disorder), physical illnesses (Parkinson's disease, Alzheimer's), and some substances such as stimulant drugs.

Caffeine-related psychiatric disorders

While rare, caffeine-induced psychosis has been reported in both clinical studies and case reports. The ''Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition'' '' – Text Revision (DSM-5-TR)'' outlines five caffeine-related syndromes, including caffeine-induced anxiety disorder, caffeine-induced sleep disorder, and unspecified caffeine-related disorders, under stimulant-related diagnostic codes. The '' International Classification of Diseases, Tenth Revision (ICD-10)'' classifies disorders associated with caffeine more broadly, as "mental and behavioural disorders due to use of other stimulants, including caffeine".

Several case studies and reviews have suggested that excessive caffeine intake may provoke psychotic or manic symptoms in vulnerable individuals. Caffeine may also worsen recovery in patients with bipolar disorder or pre-existing psychotic conditions, such as schizophrenia, which has led some clinical guidelines to recommend reducing or eliminating caffeine intake during psychiatric treatment, particularly for mania.

Some case reports suggest that psychotic symptoms can emerge in individuals without a history of mental illness after consuming high doses of caffeine. Though not conclusively confirmed, it is hypothesized that caffeine may exacerbate underlying paranoid traits or lower the threshold for developing psychopathology in those predisposed to psychosis. Symptom resolution following caffeine discontinuation has been observed in several cases, which supports the existence of caffeine-induced psychosis.

Mechanisms

Caffeine acts as an antagonist of adenosine receptors, particularly A1 and A2A receptors. Under normal conditions, adenosine inhibits neurotransmission, which promotes sleep and suppresses arousal. By blocking these receptors, caffeine limits adenosine's inhibitory influence, which results in increased neuronal activity and the enhanced release of excitatory neurotransmitters, such as dopamine and glutamate.

This mechanism contributes to improved alertness, attention, and mood at moderate doses. However, high doses or chronic overuse may overstimulate dopamine pathways in the brain, particularly in areas like the mesolimbic system, which are associated with the development of psychotic symptoms.

The elevated dopaminergic activity resembles the neurochemical abnormalities observed in psychotic disorders to a lesser degree, and may trigger hallucinations, delusions, or manic symptoms, particularly in individuals who are genetically or biologically vulnerable.

Additionally, caffeine-induced sleep deprivation, anxiety, and increased arousal can further exacerbate the risk of psychotic symptoms, either independently or in combination with other stressors or substances.

Epidemiology

In healthy individuals

While rare, caffeine-induced psychosis can occur in healthy individuals, particularly under conditions of sleep deprivation, stress, or concurrent substance use. Clinical management varies by severity, with some individuals recovering spontaneously after caffeine cessation and others requiring repeated psychiatric hospitalization or medication.

While caffeine is widely consumed for its stimulant effects, excessive intake has been associated with the onset of acute psychotic symptoms in individuals without prior psychiatric diagnoses. A growing number of case reports have described caffeine-induced psychosis in otherwise healthy individuals, with symptoms typically resolving after caffeine cessation, although some cases necessitated psychiatric treatment.

Case report evidence suggests that caffeine may precipitate psychotic symptoms in otherwise healthy individuals, although a definitive causal relationship has not been established. Caffeine's effect on dopamine levels may increase arousal and contribute to the onset of psychotic symptoms. Additionally, symptom improvement has been observed following caffeine reduction in individuals with pre-existing psychotic disorders. These findings suggest that individuals with a predisposition to psychosis may possess a lower threshold for developing psychopathological symptoms in response to caffeine intake.

In individuals with schizophrenia

Eighty percent of people with schizophrenia smoke daily and are heavy smokers. Smoking tends to deplete much of ingested caffeine, so the majority of users with schizophrenia have to consume much more caffeine than others to regulate their caffeine levels.

Many people with schizophrenia use caffeine to combat boredom or to fight the sedating effects of antipsychotic medications. Additionally people with schizophrenia may have polydipsia (causes someone to feel an immense amount of thirst, despite already drinking plenty of hydrating fluids), so people with this disorder may try to consume more caffeine than normal. A lot of antipsychotic medications contain ingredients that make the mouth more prone to dryness, which would also increase the amount of coffee (containing caffeine) one may uptake.

"Caffeine use can cause restlessness, nervousness, insomnia, rambling speech, and agitation" worsening the symptoms of schizophrenia. "Caffeine is metabolized by the CYP1A2 enzyme and also acts as a competitive inhibitor of this enzyme. Thus, caffeine can interact with a wide range of psychiatric medications, including antidepressant agents, antipsychotic agents, antimanic agents, antianxiety agents, and sedative agents."

A consumption of less than 250 mg of caffeine a day has been seen to give better results in better performances on cognitive tasks in people with schizophrenia. Although, more research still needs to be done to determine if the same amount of caffeine that is safe to consume by schizophrenics (> 250 mg/a day) matches up with the general population of people without schizophrenia.

Treatment and prevention

For schizophrenic people that have an addiction to caffeine, the best way to treat caffeine-induced psychosis is to gradually consume smaller amounts of it over a period of time. Withdrawal to certain drugs may worsen side effects of any psychotic or mood disorders. For people who consume excessive amounts of caffeine without a prior psychotic disorder, a doctor may prescribe antipsychotics to help stop the effects of psychosis.

References

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Caffeine
Psychosis
Schizophrenia