Can magic mushrooms cause psychosis or schizophrenia? What the evidence shows

Can magic mushrooms cause psychosis? Case reports say it can happen in some people, but the research cannot yet say who, how often or at what level of risk. The evidence has three kinds of source: a small pile of case reports, a few large surveys, and clinical trials that mostly keep out the people most likely to be affected. Each answers a different question, and none settles this one.

We label claims the same way throughout. Established: shown in peer-reviewed work and not seriously disputed. Preliminary: early, small, indirect or based on self-report. Unresolved: the data are missing or point different ways. This is a description of research, not medical, legal or personal advice, and it never says what any person should do.

Can magic mushrooms cause psychosis? What the evidence adds up to

Three findings recur. First, case reports describe psychotic episodes after psilocybin use, and a published review of such reports found that every case had a prior history of substance use problems, psychiatric symptoms or both (Morris, 2024). Second, large general-population surveys of lifetime use mostly find no raised rate of psychotic symptoms on average (Krebs and Johansen, 2013). Third, careful trials screen out people with psychotic disorders, partly because of this concern (Johnson et al., 2008).

These can all be true together. A drug can leave most users unaffected and still trigger problems in a vulnerable few, which averages in a survey would hide. The reverse is also possible: apparent cases may be coincidence, since psychosis usually first appears in the late teens or early twenties (CAMH). The table sets out what each kind of evidence can and cannot show.

Is a frightening mushroom trip the same as psychosis?

No. They can look alike from the outside, but the terms mean different things. CAMH describes psychosis as conditions in which people have trouble telling what is real from what is not, with symptoms such as hallucinations and delusions, and says an episode usually first appears in the late teens or early twenties (CAMH). Schizophrenia is a diagnosis: some psychotic symptoms for at least six months, with a significant decline in functioning (CAMH).

A psychedelic experience is different in time and cause. Researchers who write safety guidelines name overwhelming distress during the drug's action, the "bad trip", as the most likely risk, and describe prolonged psychoses as less common (Johnson et al., 2008). In eight placebo-controlled studies that pooled 110 healthy volunteers, strong dysphoria or anxiety and panic occurred in a relatively small share of sessions, all were managed with interpersonal support, and follow-up found no prolonged psychosis (Studerus et al., 2011). Evidence: established, but for screened, prepared volunteers in a monitored research setting.

Outside the lab the picture is less tidy. In an online survey of 1,993 people about their single worst bad trip on mushrooms, 11% said they put themselves or others at risk of harm, 2.6% were physically aggressive or violent and 2.7% received medical help. Of those whose experience was more than a year earlier, 7.6% sought treatment for enduring psychological symptoms, and three cases appeared associated with the onset of enduring psychotic symptoms (Carbonaro et al., 2016). Evidence: preliminary. It asked people about their worst experience, so it cannot give a rate per user or per session.

Two further points. CAMH says that in substance-induced psychosis the symptoms can sometimes resolve once the substance wears off, but other times need medical treatment (CAMH). And hallucinogen persisting perception disorder, a separate condition of lasting perceptual changes, is described in safety guidance as relatively rare (Johnson et al., 2008).

Why do psilocybin trials exclude people with psychotic disorders?

Because investigators treat the risk as real enough to avoid. The widely cited 2008 safety guidelines for human hallucinogen research list excluding volunteers with a personal or family history of psychotic disorders, or other severe psychiatric disorders, as one safeguard against prolonged psychosis (Johnson et al., 2008). Evidence: this is established as practice. It is not proof of how large the risk is.

• Johns Hopkins depression trial (2021): adults were eligible only with no personal or family history, first or second degree, of psychotic or bipolar disorders. In its screening, 77 people were ruled out because a relative had a schizophrenia-spectrum, bipolar or other psychotic disorder (Davis et al., 2021).
• COMPASS Pathways phase 3 depression trials (COMP005 and COMP006): the registry lists as a key exclusion any prior or ongoing bipolar disorder or psychotic disorder, including schizophrenia, schizophreniform, schizoaffective and brief psychotic disorder, unless substance-induced or due to a medical condition. It also excludes lifetime paranoid, schizoid and schizotypal personality disorders (ClinicalTrials.gov, COMP005; COMP006). We read the listed key criteria only, so we do not claim anything about family-history rules in those trials.

A 2025 systematic review and meta-analysis made the exclusion itself a question. Its authors pooled 131 publications and concluded that schizophrenia might not be a definite exclusion criterion for trials in some conditions, but also that the studies were mostly low quality and few, so a conservative approach is recommended until better data exist (Sabé et al., 2025). Evidence: preliminary. The practical result is that how psilocybin affects people with psychotic disorders remains largely untested, because the trials that would test it keep them out.

What do case reports of lasting psychosis after mushrooms show?

A 2024 case report described a man who developed psychotic and catatonic symptoms, with suicidal thoughts, after several months of heavy psilocybin use. He also had a history of depression, schizoid and avoidant personality traits that the authors describe as possible antecedents of schizophrenia, and years of cannabis use. The authors reviewed eight earlier case reports covering nine cases. Every case had a personal history of substance use problems, psychiatric symptoms or both, six had known cannabis use, and six involved repeated or unusually large amounts (Morris, 2024).

Another report described a young patient who used a large amount of psilocybin and developed a first psychotic and manic episode complicated by violent behaviour and muscle breakdown (Suleiman et al., 2022).

What these show: psychotic episodes can follow psilocybin use, and the reported cases cluster in people with other risk factors. What they cannot show: how often it happens, whether the mushrooms caused it, triggered it in someone already heading toward illness, or merely came first. The 2024 authors themselves note that it is unclear what role cannabis played and that depression may have masked early signs of illness (Morris, 2024). Evidence: preliminary.

The authors of the 2013 survey study offer cautions about case reports. They argue that mental illness and psychedelic use are both common, which makes chance overlap likely, and that both tend to begin in late adolescence and early adulthood. They also note most reports do not rule out earlier difficulties or other drugs, and that some people attribute symptoms to a drug even when they began months or years later (Krebs and Johansen, 2013). These are their arguments, not settled fact, but they are reasons to read any single report carefully.

What do large population surveys say about psychedelics and mental health?

Krebs and Johansen, 2013: no average link

This analysis used US National Survey on Drug Use and Health data, 2001 to 2004: 130,152 adults, of whom 21,967 reported lifetime psychedelic use. It examined distress, mental health treatment, symptoms of eight psychiatric disorders including non-affective psychosis, and seven specific psychotic symptoms. After adjusting for background factors, other drug use and trauma exposure, there were no significant associations between lifetime use of psychedelics, or of LSD, psilocybin, mescaline or peyote individually, and increased rates of any outcome. The authors concluded they did not find psychedelic use to be an independent risk factor for mental health problems (Krebs and Johansen, 2013).

Their listed limits matter just as much. The design was retrospective and cross-sectional, so cause cannot be inferred. Important risk factors such as family mental health history were not available, and there was no data on mental health before first use. Screening questions rather than diagnostic interviews were used, doses and purity of street drugs were unknown, and the authors wrote they cannot exclude a negative effect for some individuals or groups that might be offset at population level by positive effects in others. The psychosis data covered only 2001 and 2002 (Krebs and Johansen, 2013). Evidence: preliminary.

Hendricks and colleagues, 2015: a different question

This study is easy to misread, so it is worth being exact. Using pooled US survey data from over 190,000 adults (2008 to 2012), it found lifetime classic psychedelic use associated with lower odds of past-month psychological distress and of suicidal thinking, planning and attempts. Its stated outcomes were distress and suicidality, not psychosis (Hendricks et al., 2015). So it speaks to a neighbouring question and is not evidence either way on psychosis. Associations in such surveys are also not evidence that psychedelics prevent or treat anything.

Newer studies of psychotic symptoms, 2024 and 2025

Four recent studies looked specifically at psychotic symptoms. They use symptom questionnaires, not clinical diagnoses, and they measure psychedelics in general, not only psilocybin. Their results are mixed.

• Honk et al., 2024: about 9,700 adults from samples representative of the US and UK, followed for two months. Psychedelic use was not associated with a change in the number of psychotic symptoms, unless it interacted with a personal or family history of bipolar disorder (symptoms rose) or a personal history of psychotic disorders (symptoms fell) (Honk et al., 2024).
• Simonsson et al., 2024: 16,255 Swedish adolescent twins at age 15, of whom 541 reported psychedelic use and almost all (99%) also reported other drugs. After adjusting for other drug use, psychedelic use was associated with fewer psychotic symptoms. For manic symptoms there were interactions with genetic vulnerability to schizophrenia or bipolar I disorder. The authors stressed caution and the need for replication, and the study had no data on dose, frequency or setting (Simonsson et al., 2024).
• Simonsson et al., 2025: a purposive sample of 21,990 US adults aged 18 to 50, with 12,345 completing a follow-up two months later and 505 reporting psychedelic use in that window. Psychedelic use was associated with increases in the severity of psychotic and manic symptoms, but only among those who reported use in an illegal context. Psychotic symptom increases appeared to depend on frequency and on the intensity of challenging experiences (Simonsson et al., 2025).
• Dourron et al., 2025: a cross-sectional survey of 548 people, designed to include those with a personal or family history of psychotic or bipolar disorders. After adjustment, lifetime number of psychedelic occasions was not associated with any measured psychotic symptom (Dourron et al., 2025).

Read the 2025 Simonsson study with its own limits in view. Its authors note the sample was chosen to include likely psychedelic users, follow-up loss was high, only 4 participants with a personal history of schizophrenia and 22 with bipolar I disorder used psychedelics in the window, and only 33 used in a non-illegal context. All answers were self-reported. The authors also say the study did not assess whether the symptom increases were clinically meaningful, so it does not show who developed a disorder (Simonsson et al., 2025). The authors report that 97% of the users' most intense experiences took place in an illegal context, so the legal-versus-illegal comparison rests on very few people. Why legal status would matter, whether through setting, preparation, product or something else, is not answered. Evidence: preliminary.

A 2026 review of studies on young people under 18 found that in community samples, hallucinogen use showed weak and inconsistent associations with psychotic and manic symptoms, largely attenuated after adjusting for other drugs and genetic vulnerability. Its authors still concluded that hallucinogens, though not an isolated causal trigger, may contribute to symptom exacerbation in neurodevelopmentally or genetically predisposed youth (Armanino-Irigaray et al., 2026). Evidence: preliminary.

Do magic mushrooms cause schizophrenia?

Nobody has shown that they do, and nobody has shown they cannot. The best available pooled estimate does not answer it directly. The 2025 meta-analysis put the incidence of psychedelic-induced psychosis at 0.002% in population studies, 0.2% in uncontrolled trials and 0.6% in randomized trials, from nine studies, with the authors warning that most of the underlying work was low quality. The studies pooled several psychedelics, not psilocybin alone (Sabé et al., 2025). Evidence: preliminary.

The same review reports the figure that worries clinicians most: across three follow-up studies of 353 people whose substance-induced psychotic disorder involved hallucinogens as their main drug, 13.1% were later diagnosed with schizophrenia, over an average of 10.5 years. These were hallucinogens in general, not psilocybin alone. The review's abstract also reports that in uncontrolled trials that included people with schizophrenia, 3.8% developed long-lasting psychotic symptoms. That figure rests on two non-randomized studies of 133 patients given one to three sessions of LSD, published more than half a century ago, and the authors add that almost all of those patients showed no long-lasting symptoms (Sabé et al., 2025). Neither figure shows that a drug produced a lasting illness. An early episode may have been the first sign of a condition that was already starting, and CAMH notes it is usually hard to tell the exact type of a psychotic disorder in the early phases (CAMH). Evidence: unresolved.

What is still unknown about magic mushrooms and psychosis?

• How often lasting psychosis follows psilocybin use in the general population. The pooled estimates rest on few, low-quality studies and combine different drugs (unresolved).
• Whether psilocybin can start a lasting psychotic disorder in someone who would not otherwise have developed one, or only brings forward an illness that was coming (unresolved).
• Who is most vulnerable. Case reports point to people with prior psychiatric history, cannabis use and heavy or repeated use, but this comes from a handful of cases (preliminary).
• What happens to people with a psychotic disorder or a family history when they use psilocybin. Trials mostly keep them out, and the surveys that include them are small (unresolved).
• Whether dose, setting, preparation or legal context change the risk. The 2025 survey suggests a pattern but cannot explain it, and strength varies widely between mushrooms, so amounts are rarely known outside a lab (unresolved).
• The long-term course of people who had a psychotic episode after use. Most studies follow people for months at most (unresolved).

Funding and interests matter too. The competing-interest statement of the 2025 Simonsson study lists ties between some of its authors and companies in the psychedelic field (Simonsson et al., 2025). That is not a reason to reject the data, but it is a reason to wait for independent replication. For a wider view of psilocybin's effects on the brain, see our guide on whether psilocybin rewires the brain.

Where can someone get help in Canada?

• Immediate danger or urgent medical need: call 911 (Government of Canada).
• Thoughts of suicide, or worry about someone else: call or text 9-8-8, available 24 hours a day, 7 days a week (Government of Canada).
• Possible psychosis: CAMH advises taking someone to the nearest emergency department in urgent situations, such as when there is potential harm (CAMH).
• In Toronto, CAMH lists Access CAMH, its centralized information, intake and scheduling line, at 416-535-8501, option 2 (CAMH). For mental health services CAMH says a healthcare provider must complete a referral form, and for addictions services people can refer themselves.
• Elsewhere in Canada: the federal get-help page lists provincial and territorial resources, and suggests contacting a family physician, psychologist, mental health nurse or social worker (Government of Canada).

CAMH adds that psychosis is treatable and that many people with it go on to lead full, meaningful lives (CAMH). Our safety page keeps these pointers in one place. If you are worried about someone during a difficult experience right now, read our guide to helping someone having a bad trip and use the emergency options above if there is any risk.

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