Recreational cannabis use over time in individuals at clinical high risk for psychosis: Lack of associations with symptom, neurocognitive, functioning, and treatment patterns.
Ricardo E Carrión, Andrea M. Auther, Danielle McLaughlin, S. Adelsheim, Cynthia Z. Burton, C. Carter, T. Niendam, J. Ragland, Tamara G. Sale, S. Taylor, Ivy F. Tso, W. McFarlane, Barbara Cornblatt
Psychiatry Research August 1, 2023 DOI: 10.1016/j.psychres.2023.115420 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Population | Youth at clinical high risk (CHR) for psychosis |
| Duration | 2-year follow-up |
| Topics | Cannabis |
| Key findings | Among CHR youth followed for two years, continuous cannabis users showed higher neurocognition and social functioning over time and decreased medication usage compared with non-users. Clinical symptoms improved over time despite the medication decreases, a pattern the authors describe as surprising given expectations that cannabis worsens outcomes in this population. |
Abstract
Recreational cannabis use has recently gained considerable interest as an environmental risk factor that triggers the onset of psychosis. To date, however, the evidence that cannabis is associated with negative outcomes in individuals at clinical high risk (CHR) for psychosis is inconsistent. The present study tracked cannabis usage over a 2-year period and examined its associations with clinical and neurocognitive outcomes, along with medication rates. CHR youth who continuously used cannabis had higher neurocognition and social functioning over time, and decreased medication usage, relative to non-users. Surprisingly, clinical symptoms improved over time despite the medication decreases.
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 |
Citations in the library
Cited by 2
- Cannabis and Tobacco Co-Use Is Associated With Impaired Neurocognitive Performance in Individuals at Clinical High Risk for Psychosis. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging April 1, 2026
- Occasional cannabis use is associated with higher premorbid functioning and IQ in youth at clinical high-risk (CHR) for psychosis: Parallel findings to psychosis cohorts Schizophrenia Research July 30, 2024
Cites 4
- Traditional marijuana, high‐potency cannabis and synthetic cannabinoids: increasing risk for psychosis World Psychiatry September 22, 2016
- 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 Schizophrenia Bulletin July 25, 2010
- Alcohol confounds relationship between cannabis misuse and psychosis conversion in a high‐risk sample Acta Psychiatrica Scandinavica January 9, 2015
- Prospective study of cannabis use in adolescents at clinical high risk for psychosis: impact on conversion to psychosis and functional outcome Psychological Medicine December 1, 2012