science

Hallucinogen-induced psychotic disorder

Hallucinogen-induced psychotic disorder is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Hallucinogen-induced psychotic disorder rather than just read about it. In short: Hallucinogen-induced psychotic disorder (HIPD), also known as hallucinogen-induced psychosis or psychedelic-induced psychosis, is a mental disorder characterized by psychotic symptoms such as hallucinations, delusions, severe paranoia, disorganized thinking and behavior, and insomnia. Hallucinogen-induced psychotic disorder occurs following the use of hallucinogens, for instance dissociatives like phencyclidine (PCP…

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Reference excerpt

Hallucinogen-induced psychotic disorder (HIPD), also known as hallucinogen-induced psychosis or psychedelic-induced psychosis, is a mental disorder characterized by psychotic symptoms such as hallucinations, delusions, severe paranoia, disorganized thinking and behavior, and insomnia. Hallucinogen-induced psychotic disorder occurs following the use of hallucinogens, for instance dissociatives like phencyclidine (PCP), cannabinoids like cannabis, and psychedelics like LSD. The incidence rate of HIPD with psychedelics is 0.002% to 0.6% in different types of studies and is considered to be low and rare. HIPD with psychedelics is more likely to occur in individuals with a personal or family history of mental illness and is far more likely to occur in people with schizophrenia. The treatment is atypical antipsychotic medication. Hallucinogen-induced psychotic disorder may last for weeks or months if left untreated.

Signs and symptoms The symptoms of hallucinogen-induced psychotic disorder involve the symptoms of psychosis such as severe paranoia, confusion, agitation, hallucinations, delusions, disorganized thinking, and disorganized behavior. Memory problems and insomnia may also occur. The symptoms typically begin shortly after using a hallucinogen and continue until they are treated with an antipsychotic medication. The symptoms of hallucinogen-induced psychotic disorder are similar to those of schizophrenia and it may have a similar underlying genetic vulnerability.

Causes

Dissociatives Dissociatives like phencyclidine (PCP) and ketamine are said to be strongly linked to hallucinogen-induced psychotic disorder.

Cannabinoids Cannabinoids such as cannabis and especially synthetic cannabinoids can induce psychosis.

Psychedelics LSD is a known cause of hallucinogen-induced psychotic disorder. It is the most common psychedelic in emergency department visits, being responsible for 47.3% of all cases of psychedelic-induced psychosis. Psilocybin can cause hallucinogen-induced psychotic disorder after brief or intermittent use. There are several case studies of psilocybin-induced psychosis. A 25-year-old woman was treated with olanzapine for hallucinogen-induced psychotic disorder caused by psilocybin. A 30-year-old man was also successfully treated with olanzapine for hallucinogen-induced psychotic disorder caused by psilocybin. In emergency departments, psilocybin is responsible for 18.8% of all cases of psychedelic-induced psychosis. There are case reports of mescaline causing hallucinogen-induced psychotic disorder. In one case, a 41-year-old man was successfully treated with first risperidone, then aripiprazole for HIPD caused by mescaline. Dimethyltryptamine (DMT) is known to cause hallucinogen-induced psychotic disorder. There are case reports of DMT-induced psychosis. In one case, a 42-year-old man was successfully treated with quetiapine for hallucinogen-induced psychotic disorder caused by DMT. In another case, a 25-year-old male was successfully treated with paliperidone for hallucinogen-induced psychotic disorder caused by DMT. In emergency departments, DMT is responsible for 3.2% of all cases of hallucinogen-induced psychotic disorder. Psychedelics are not thought to cause de novo psychosis but instead to exacerbate or unmask it in people with pre-existing psychotic susceptibility.

Diagnosis Hallucinogen-induced psychotic disorder has the code 6C49.5 in the ICD-11.

Differential diagnosis Hallucinogen persisting perception disorder (HPPD) involves lasting visual changes after use of a hallucinogenic drug. Hallucinogen persisting perception disorder is not a psychotic disorder. It is a long-term visual condition most often found among frequent hallucinogenic drug users.

Treatment

Treatment consists of atypical antipsychotics such as risperidone, olanzapine, aripiprazole, or quetiapine. Haloperidol, a typical antipsychotic may be given in the emergency room to stabilize a patient before they are switched to an atypical antipsychotic for maintenance therapy. If the hallucinogen is still active in an individual's system, risperidone is recommended directly as a first-line hallucinogen antidote, or trip killer. Aripiprazole, brexpiprazole, cariprazine, and lurasidone are third-generation antipsychotics used to treat substance-induced psychosis. Compared to second and first-generation antipsychotics, third-generation antipsychotics have a better side effect profile and improved tolerability for long-term use. Individuals are also recommended to practice abstinence from hallucinogens and can be given counseling designed to assist with preventing a relapse of substance use.

Prognosis Hallucinogen-induced psychotic disorder is later diagnosed as schizophrenia in approximately 13 to 26% of individuals. A rate of 13% has been found with psychedelics in a 2025 study and a rate of 26% with hallucinogens including psychedelics and phencyclidine (PCP) in an 2020 study. The rate of transition to schizophrenia with psychedelics is lower than with amphetamines (22%) and cannabis (34%). Left untreated, hallucinogen-induced psychotic disorder has sometimes led to suicide. Patients usually have an individual or family psychiatric history.

Epidemiology Psychedelic-induced psychosis has been reported to occur at rates of 0.002% of individuals in population studies, 0.2% in uncontrolled trials, and 0.6% in randomized controlled trials, with an overall rate of 0.4%. Excluding people with psychiatric disorders caused the overall rate to drop to 0.2%. In uncontrolled trials of people with schizophrenia, the rate was 3.8%, albeit based on low-quality data from the 1950s and 1960s. The risk of psychedelic-induced psychosis is considered to be low and rare for the general population when people with pre-existing schizophrenia or psychosis are excluded. In addition, it is far lower than with cannabis and psychostimulants, which have reported rates of 30 to 55%. It is also thought to be much lower than with dissociatives like phencyclidine (PCP). The quality of existing findings on incidence of psychedelic-induced psychosis is low as of 2025. Little to no data exist for some types of hallucinogens such as Salvia divinorum.

See also Substance-induced psychosis Schizophrenia Psychedelic syndrome

References

Worked examples

Example 1 — a first encounter with Hallucinogen-induced psychotic disorder

Start with the simplest possible case. Write down what Hallucinogen-induced psychotic disorder claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Hallucinogen-induced psychotic disorder before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Hallucinogen-induced psychotic disorder ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Hallucinogen-induced psychotic disorder

In research: Hallucinogen-induced psychotic disorder appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Hallucinogen-induced psychotic disorder in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Hallucinogen-induced psychotic disorder is common in secondary-school and first-year university syllabi. It links to neighbouring topics Drug culture, Effects of psychoactive drugs, Hallucinations, so understanding it makes those chapters shorter.
In everyday life: Look for Hallucinogen-induced psychotic disorder outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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Frequently asked questions

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