Cannabis-Induced Psychosis: Which Antipsychotics Best Prevent Hospitalization?
August 29, 2025 DOI: 10.64239/pi-qt7803 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort |
|---|---|
| Population | People with cannabis-induced psychosis |
| Interventions | antipsychotic medication long-acting injectable aripiprazole oral olanzapine injectable aripiprazole oral clozapine |
| Topics | Cannabis |
| Key findings | Antipsychotic medication reduced hospitalization risk by 25% for psychosis and substance use disorders, and 50% for medical conditions; long-acting injectable aripiprazole or olanzapine reduced psychosis-related hospitalization risk by 75%. |
Abstract
The prevalence of cannabis-induced psychosis has increased substantially, possibly due to higher cannabis potency and greater use. Antipsychotic medication reduced hospitalization risk by 25% for psychosis, 25% for substance use disorders, and 50% for medical conditions. For psychosis-related hospitalization, long-acting injectable aripiprazole or olanzapine reduced risk by 75%—twice as effective as oral formulations. Clozapine was also effective, while risperidone, quetiapine, and paliperidone were not. For substance use–related hospitalization, effective options included injectable or oral olanzapine, injectable aripiprazole and paliperidone, and oral clozapine and risperidone.
Comparable studies
Other observational and cohort studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| High-potency cannabis and the risk of psychosis People with first episode of psychosis and healthy controls from the local population | 2009 | Case-control study | n = 454 |
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Impaired cognitive performance in drug free users of recreational ecstasy (MDMA) Otherwise healthy young people | 2000 | Observational | |
| Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study Individuals from the general population in Germany aged 14-24 at baseline | 2011 | Observational cohort | n = 1,923 |
| Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases Patients treated for cannabis-induced psychotic symptoms in Denmark between 1994 and... | 2005 | Observational cohort | n = 535 |