Cannabis and cognitive performance in psychosis: a cross-sectional study in patients with non-affective psychotic illness and their unaffected siblings.
J H Meijer, N Dekker, M W Koeter, P J Quee, N J M Van Beveren, C J Meijer
Psychological Medicine April 2012 DOI: 10.1017/s0033291711001656 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Cross-sectional study Peer reviewed |
|---|---|
| Sample size | 2,463 |
| Population | 956 patients with non-affective psychosis, 953 unaffected siblings, and 554 control subjects |
| Measures | Composite International Diagnostic Interview |
| Topics | Cannabis |
| Key findings | Current cannabis use was associated with poorer immediate verbal learning, processing speed, and working memory (Cohen's d -0.20 to -0.33), whereas lifetime cannabis use was associated with better acquired knowledge and facial and identity recognition (Cohen's d +0.17 to +0.33). No significant cannabis-by-status interaction was found. The authors propose that lifetime cannabis users may constitute a subgroup with higher cognitive potential and that residual cannabis effects may impair short-term memory and processing speed. |
Abstract
The relationship between cannabis use and cognitive functioning in patients with psychosis has yielded contradictory findings. In individuals at genetic high risk for psychosis, information is sparse. The aim of this study was to assess the association between recency and frequency of cannabis use and cognitive functioning in patients with psychosis and their unaffected siblings. We conducted a cross-sectional study in 956 patients with non-affective psychosis, 953 unaffected siblings, and 554 control subjects. Participants completed a cognitive test battery including assessments of verbal learning, set shifting, sustained attention, processing speed, working memory, acquired knowledge, reasoning and problem solving and social cognition. Cannabis use was assessed by urinalysis and by the Composite International Diagnostic Interview. Using random-effect regression models the main effects of cannabis (recency and frequency) and the interaction with status (patient, sibling, control) on cognitive functioning were assessed. Current cannabis use was associated with poorer performance on immediate verbal learning, processing speed and working memory (Cohen's d -0.20 to -0.33, p<0.005). Lifetime cannabis use was associated with better performance on acquired knowledge, facial affect recognition and face identity recognition (Cohen's d+0.17 to +0.33, p<0.005). There was no significant interaction between cannabis and status on cognitive functioning. Lifetime cannabis-using individuals might constitute a subgroup with a higher cognitive potential. The residual effects of cannabis may impair short-term memory and processing speed.
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
Cited by 11
- Exposure to cannabinoids can lead to persistent cognitive and psychiatric disorders European Journal of Pain February 22, 2019
- Consumo de cannabis y alteraciones cognitivas en esquizofrenia y primeros episodios psicóticos Adicciones April 1, 2019
- Eye movements in patients in early psychosis with and without a history of cannabis use Schizophrenia May 12, 2021
- 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 use and cognitive biases in people with first-episode psychosis and their siblings Psychological Medicine November 1, 2024
and 6 more in the library
Cites 14
- 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
- Cannabis use and cognition in schizophrenia Frontiers in Human Neuroscience 2009
- Letter to the Editor: Drawing conclusions about cannabis and psychosis Psychological Medicine February 26, 2008
- Evidence that familial liability for psychosis is expressed as differential sensitivity to cannabis: an analysis of patient-sibling and sibling-control pairs. Archives of General Psychiatry February 2011
- Family-based analysis of genetic variation underlying psychosis-inducing effects of cannabis: sibling analysis and proband follow-up. Archives of General Psychiatry February 2011
and 9 more in the library