Your genes may determine how much cannabis affects your thinking and memory
A review of 13 studies found that genetic variations in dopamine-related genes (especially COMT) modulated how cannabis impairs working memory, attention, and other cognitive functions.
Quick Facts
What This Study Found
Researchers systematically reviewed 13 studies examining how genetic variations influence the cognitive effects of cannabis use. The most consistent finding involved the COMT gene, which regulates dopamine breakdown in the prefrontal cortex.
People with the Val variant of the COMT gene showed greater impairment in working memory, verbal and visual memory, and sustained attention during cannabis intoxication compared to those with the Met variant. The COMT gene also modulated sustained attention effects during regular cannabis use, not just acute intoxication.
Several other genes showed potential modulatory effects: the CNR1 gene (encoding the CB1 receptor), the AKT1 gene (involved in dopamine signaling), the DBH gene (involved in norepinephrine synthesis), and the serotonin transporter gene (5-HTT/SLC6A4).
The review noted that most of these genes are also linked to schizophrenia risk, suggesting that the genetic factors determining how cannabis affects cognition may overlap with those determining vulnerability to cannabis-related psychosis.
Key Numbers
13 studies included. Key gene: COMT Val allele associated with greater cognitive impairment during intoxication. Other modulatory genes identified: CNR1, AKT1, DBH, 5-HTT/SLC6A4. Cognitive domains affected: working memory, verbal memory, visual memory, sustained attention.
How They Did This
Systematic search of PubMed, Web of Science, and ScienceDirect databases for studies measuring neurocognition and assessing genotypes in the context of cannabis use. Thirteen articles meeting inclusion criteria were reviewed.
Why This Research Matters
Not everyone responds to cannabis the same way cognitively. Understanding the genetic basis of these differences could eventually enable personalized risk assessment, identifying individuals who are most vulnerable to cannabis-related cognitive impairment before they experience it.
The Bigger Picture
The overlap between genes that modulate cannabis cognitive effects and genes linked to schizophrenia provides a molecular bridge between cannabis use and psychosis risk. Understanding these shared genetic pathways could clarify the mechanisms linking cannabis to psychosis and help identify who is most at risk.
What This Study Doesn't Tell Us
Only 13 studies were available, limiting the ability to draw firm conclusions. Most studies were small and used different cognitive assessments. Gene-gene interactions were not addressed. Environmental factors that interact with genetics were largely unexplored. Replication of findings across studies was limited.
Questions This Raises
- ?Could genetic testing guide personalized advice about cannabis use?
- ?Do the same genetic variants that increase cognitive vulnerability also increase psychosis risk?
- ?Would gene-cannabis interaction research benefit from larger genome-wide association approaches?
Trust & Context
- Key Stat:
- COMT Val allele carriers showed greater cognitive impairment from cannabis
- Evidence Grade:
- This is a systematic review of a small but emerging literature, providing moderate evidence for gene-cannabis interactions on cognition.
- Study Age:
- Published in 2018. Pharmacogenomics of cannabis response is still a developing field.
- Original Title:
- The effect of interactions between genetics and cannabis use on neurocognition. A review.
- Published In:
- Progress in neuro-psychopharmacology & biological psychiatry, 82, 95-106 (2018)
- Authors:
- Cosker, E, Schwitzer, T, Ramoz, N, Ligier, F, Lalanne, L, Gorwood, P, Schwan, R, Laprévote, V
- Database ID:
- RTHC-01628
Evidence Hierarchy
Summarizes existing research on a topic.
What do these levels mean? →Frequently Asked Questions
Do genes affect how cannabis impacts your thinking?
Yes, according to this review. The COMT gene variant you carry appears to influence how much cannabis impairs your working memory, attention, and other cognitive functions. People with the Val variant showed greater impairment than those with the Met variant.
Are these the same genes linked to schizophrenia?
Yes. The review noted that most of the genes found to modulate cannabis cognitive effects are also linked to schizophrenia risk. This genetic overlap may help explain why cannabis increases psychosis risk in some individuals.
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Cite This Study
https://rethinkthc.com/research/RTHC-01628APA
Cosker, E; Schwitzer, T; Ramoz, N; Ligier, F; Lalanne, L; Gorwood, P; Schwan, R; Laprévote, V. (2018). The effect of interactions between genetics and cannabis use on neurocognition. A review.. Progress in neuro-psychopharmacology & biological psychiatry, 82, 95-106. https://doi.org/10.1016/j.pnpbp.2017.11.024
MLA
Cosker, E, et al. "The effect of interactions between genetics and cannabis use on neurocognition. A review.." Progress in neuro-psychopharmacology & biological psychiatry, 2018. https://doi.org/10.1016/j.pnpbp.2017.11.024
RethinkTHC
RethinkTHC Research Database. "The effect of interactions between genetics and cannabis use..." RTHC-01628. Retrieved from https://rethinkthc.com/research/cosker-2018-the-effect-of-interactions
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.