Prevalence of cannabis use in psychosis-affected youth: Insights from an Ontario-based early intervention cohort.
Naseem Abdulmohi Alhujaili, O. Ayonrinde
Journal of ethnicity in substance abuse April 22, 2026 DOI: 10.1080/15332640.2026.2657003 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Retrospective cross-sectional study Peer reviewed |
|---|---|
| Sample size | 116 |
| Population | Individuals aged 14-35 consecutively enrolled in an Early Psychosis Intervention program in Southeast Ontario between 2016 and 2019 |
| Topics | Cannabis |
| Key findings | Cannabis use was self-reported by 82.8% of participants and was most prevalent among males and those aged 18-25. Cannabis use was significantly associated with substance-induced psychosis diagnoses and with lower levels of formal education compared with non-users. |
Abstract
Cannabis use has long been linked to the emergence and worsening of psychotic disorders, particularly among adolescents and young adults. This study aimed to determine the prevalence of cannabis use and its psychiatric associations in youth and young adults enrolled in an Early Psychosis Intervention (EPI) program in Southeast Ontario. A retrospective cross-sectional analysis was conducted on 116 individuals aged 14-35 who were consecutively enrolled in the EPI program between 2016 and 2019. Data on demographic characteristics, psychiatric diagnoses, and self-reported cannabis use were extracted from clinical records. Statistical analyses were performed to examine associations between cannabis use and variables such as age, gender, educational background, and psychiatric comorbidities. Cannabis use was self-reported by 82.8% of participants. The majority of users were male, and use was most prevalent among individuals aged 18-25. A significant association was found between cannabis use and diagnoses of substance-induced psychosis (p < 0.001). Lower levels of formal education were more frequent among cannabis users compared to non-users (p = 0.004).This study identified a strikingly high rate of cannabis use among youth engaged in early psychosis care, particularly among males and young adults in their early twenties. The findings underscore the importance of routine screening, targeted psychoeducation, and harm reduction strategies within EPI programs. Given the strong association with substance-induced psychosis, early identification and integrated treatment approaches are essential to improve long-term outcomes in this population.
Comparable studies
Other cross-sectional and survey studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Cannabis use before age 15 and subsequent executive functioning 104 chronic cannabis users (49 early-onset before age 15, 55 late-onset after age 15)... | 2011 | Observational cross-sectional study | n = 148 |
| Patterns of simultaneous polysubstance use in drug using university students Drug-using university students | 2006 | Cross-sectional survey | n = 149 |
| Persisting Reductions in Cannabis, Opioid, and Stimulant Misuse After Naturalistic Psychedelic Use: An Online Survey Online survey respondents | 2020 | Cross-sectional survey | |
| User perceptions of the benefits and harms of hallucinogenic drug use: A web-based questionnaire study Users of hallucinogenic drugs who completed a web-based questionnaire | 2010 | Cross-sectional survey | n = 600 |
| Illicit Use of LSD or Psilocybin, but not MDMA or Nonpsychedelic Drugs, is Associated with Mystical Experiences in a Dose-Dependent Manner Adults recruited from the MAPS website and newsletter, most reporting use of various... | 2012 | Cross-sectional survey | n = 337 |
Citations in the library
Cites 4
- Which biological and self-report measures of cannabis use predict cannabis dependency and acute psychotic-like effects? Psychological Medicine September 4, 2018
- Cannabis use and nonuse in patients with first-episode psychosis: A systematic review and meta-analysis of studies comparing neurocognitive functioning European Psychiatry 2020
- Cannabis and psychosis: revisiting a nineteenth century study of ‘Indian Hemp and Insanity’ in Colonial British India Psychological Medicine May 27, 2019
- The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study The Lancet Psychiatry May 1, 2019