The relationship between cannabis use and cognition in people diagnosed with first-episode psychosis.
Chloé de Vos, Karolina Leopold, Elisabeth S. Blanke, Stefan Siebert, Johanna Baumgardt, E. Burkhardt, Andreas Bechdolf
Psychiatry Research August 23, 2020 DOI: 10.1016/j.psychres.2020.113424 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 89 |
| Population | People diagnosed with first-episode psychosis |
| Topics | Cannabis |
| Key findings | Cannabis use was not associated with cognitive impairments in verbal memory, verbal fluency, or attention among people with first-episode psychosis. |
Abstract
Cannabis use is highly prevalent among young people diagnosed with first-episode psychosis (FEP), however, its impact on cognition is still unclear. The aim of the present study was to examine the association of cannabis use with cognition in people diagnosed with FEP. We extended previous research findings by operationalising the comorbid cannabis use, considering recency of cannabis use and use of other illicit substances and including people with a broad spectrum of psychotic diagnoses. A total of 89 people diagnosed with FEP were interviewed about their history of substance use and completed a cognitive test battery assessing verbal memory, verbal fluency and attention. Sixty-one participants were lifetime cannabis users (CU; ≥three times per week for ≥four weeks; 68.5%) and 28 were cannabis non-users (CNU; 31.5%). CU were significantly more likely to be male and exhibited significantly more positive symptoms than CNU. In contrast, CNU displayed significantly more negative symptoms than CU. There were no differences between CU and CNU on neurocognitive tasks of verbal memory, verbal fluency and attention. In conclusion, there was no indication that cannabis use was associated with cognitive impairments in people diagnosed with FEP.
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 8
- Association between cannabis use and symptom dimensions in schizophrenia spectrum disorders: an individual participant data meta-analysis on 3053 individuals EClinicalMedicine September 8, 2023
- Multi-dimensional recovery trajectories in cannabis-induced psychosis: A systematic review examining symptomatic, functional, cognitive, and subjective outcomes. Asian Journal of Psychiatry April 1, 2026
- 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
- Cannabis and psychopathology: 2024 Snapshot of a meandering journey Indian Journal of Psychiatry March 1, 2025
- Does cannabis affect cognitive functioning in patients with schizophrenia? Schizophrenia Research: Cognition December 20, 2023
and 3 more in the library
Cites 7
- High-potency cannabis and the risk of psychosis The British Journal of Psychiatry November 30, 2009
- 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
- The Effect of Cannabis Use and Cognitive Reserve on Age at Onset and Psychosis Outcomes in First-Episode Schizophrenia Schizophrenia Bulletin March 9, 2011
- Familial Predisposition for Psychiatric Disorder Archives of General Psychiatry November 3, 2008
- Does Cannabis Composition Matter? Differential Effects of Delta-9-tetrahydrocannabinol and Cannabidiol on Human Cognition Current Addiction Reports April 29, 2017
and 2 more in the library