Cannabis use preceded early‐onset psychosis and was associated with worse outcomes
Alcoholism & Drug Abuse Weekly August 10, 2026 DOI: 10.1002/adaw.35011 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review and meta-analysis Peer reviewed |
|---|---|
| Sample size | 3,473 |
| Population | People with early-onset psychosis, average age about 16, 59% male, drawn from 40 studies |
| Topics | Cannabis |
| Key findings | Pooled prevalence of current cannabis use in early-onset psychosis was 32.8%, lifetime use 40.2%, and lifetime cannabis use disorder 36.6%. Cannabis use preceded psychosis onset and was associated with longer duration of untreated psychosis and higher hospitalization rates, though current use was also associated with less severe symptoms and a lower proportion of schizophrenia diagnoses. The authors argue screening and substance use care should be embedded in primary care for youth. |
Abstract
Cannabis use and cannabis use disorder (CUD) are common in early‐onset psychosis. Clinical presentation is key when determining which is present and which to treat first. But reducing cannabis use would help. A study published in the Journal of the American Academy of Child and Adolescent Psychiatry found that cannabis use preceded the psychosis symptoms. Researchers found that screening and substance use care should be embedded in primary care for youth, and they urge more efforts to reduce both cannabis use and CUD. The objective of the systematic review was to quantify the prevalence of both cannabis use and CUD in early‐onset psychosis. The researchers also wanted to examine the correlates, as well as clinical and functional impact, of both cannabis use and CUD. They reviewed six databases for studies evaluating cannabis use and CUD in early‐onset psychosis. They identified 40 studies, with 3,473 participants aged about 16, with 59% males. Pooled prevalence for current cannabis use was 32.8%, and 40.2% for lifetime use. Prevalence for lifetime CUD was 36.6%. Current cannabis use was associated with being male and being hospitalized but with less severe symptoms and a lower proportion of a schizophrenia diagnosis. Lifetime cannabis use was associated with cocaine use and also less severe negative symptoms. The researchers found that cannabis use preceded the onset of psychosis. Participants who had used cannabis also had more negative outcomes, such as a longer duration of untreated psychosis and higher hospitalization rates. The senior author of the study, “Systematic Review and Meta‐Analysis: Prevalence, Correlates, and Impact of Cannabis Use and Cannabis Use Disorder in Early‐Onset Psychosis,” is Chris Correll, M.D. It was published online June 22.
Comparable studies
Other systematic reviews and meta-analyses on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Effects of cannabis use on outcomes of psychotic disorders: systematic review People with psychotic disorders, as examined in 13 longitudinal studies | 2008 | Systematic review | |
| The Impact of Cannabis Use on Cognitive Functioning in Patients With Schizophrenia: A Meta-analysis of Existing Findings and New Data in a First-Episode Sample Patients with established schizophrenia (meta-analysis: 572) and patients with... | 2010 | Meta-analysis and cross-sectional observational study | n = 700 |
| Medicinal cannabis for psychiatric disorders: a clinically-focused systematic review | 2020 | Systematic review | |
| Neuroimaging in cannabis use: a systematic review of the literature Cannabis users and controls in neuroimaging studies | 2009 | Systematic review | |
| Human Laboratory Studies on Cannabinoids and Psychosis. Healthy human subjects and individuals with schizophrenia | 2016 | Systematic review |