Does cannabis affect cognitive functioning in patients with schizophrenia?
H. Rachid, Zineb Saif, Salma Raoui, Z. Serhier, Mohamed Agoub
Schizophrenia Research: Cognition December 20, 2023 DOI: 10.1016/j.scog.2023.100299 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Cross-sectional observational study Peer reviewed |
|---|---|
| Sample size | 99 |
| Population | Moroccan patients diagnosed with schizophrenia (50 cannabis users and 49 non-users) recruited at a university psychiatric centre |
| Intervention | Cannabis use |
| Measures | CogState neuropsychological battery |
| Topics | Cannabis |
| Key findings | Among patients with schizophrenia, cannabis users performed worse on psychomotor function, attention, and verbal memory but better on working memory, visual memory, and emotional recognition than non-users; no group difference was found for executive function. The authors suggest cannabis use may have differing effects across cognitive domains. |
Abstract
Introduction: Cannabis use impairs cognitive performance in healthy subjects; several studies have shown improved cognitive outcomes in schizophrenic patients using cannabis. The aim of this study was to evaluate the effects of cannabis use on cognitive function in Moroccan patients with schizophrenia who were cannabis users.
Method: Two groups were recruited in a Moroccan University Psychiatric Centre. Fifty patients diagnosed with schizophrenia according to the DSM-V who were cannabis users (SZ CANN +) and forty-nine patients diagnosed with schizophrenia according to DSM-V who do not use cannabis (SZ CANN-). Cognitive functioning was assessed using the CogState neuropsychological battery.
Results: The results of the study suggest that SZ CANN- patients performed better in the test of psychomotor function, attention and verbal memory. While SZ CANN+ patients performed better in the test of working memory, visual memory and emotional recognition. We found no relationship between SZ CANN+ patients and SZ CANN- patients concerning executive function.
Conclusions: Our results suggest that cannabis use may have different effects on neurocognitive functioning. It is associated with disorders of psychomotor function, attention and verbal memory. So, it is associated with an improvement in working memory, visual memory and emotion recognition.
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 15
- Causal association between cannabis and psychosis: examination of the evidence The British Journal of Psychiatry January 30, 2004
- Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug Brazilian Journal of Medical and Biological Research April 1, 2006
- Cannabis use and nonuse in patients with first-episode psychosis: A systematic review and meta-analysis of studies comparing neurocognitive functioning European Psychiatry 2020
- Neurocognitive functions of heavy cannabis using schizophrenia patients European Psychiatry June 28, 2011
- The relationship between cannabis use and cognition in people diagnosed with first-episode psychosis. Psychiatry Research August 23, 2020
and 10 more in the library