Genetic Predisposition to Cannabis Use Was Linked to Higher Cognitive Scores in Children | Research

The takeaway

Among 3,205 substance-naive children ages 9-10, those with higher polygenic risk for lifetime cannabis use scored better on general ability, executive function, and learning/memory tests.

Genetics researchers; neurodevelopmental scientists; anyone interested in the complexity of substance-use genetics.

Genetic risk for cannabis USE (not disorder) linked to higher cognition in children

What the researchers found

Polygenic risk for lifetime cannabis use was positively associated with all three cognitive facets: general ability, executive function, and learning/memory (Bs ≥ 0.045, qs ≤ 0.044). No other substance polygenic risk scores (alcohol, tobacco, problematic cannabis use) showed significant cognitive associations.

Why it matters

This finding is counterintuitive: genes associated with trying cannabis are also associated with better cognition in children who have never used any substances. This suggests the genetic overlap reflects shared traits like curiosity or openness to experience rather than cannabis itself improving cognition.

The numbers in context

3,205 substance-naive children, ages 9-10. Cannabis use polygenic risk associated with: general ability (B≥0.045, q≤0.044), executive function, and learning/memory. Polygenic risk for cannabis use disorder showed no cognitive association. No significant associations for alcohol or tobacco polygenic scores.

How the study worked

Cross-sectional analysis of 3,205 substance-naive European-ancestry children from the ABCD Study baseline session. Polygenic risk scores for lifetime use and problematic use of alcohol, tobacco, and cannabis were estimated from genome-wide association studies. Cognitive abilities were measured using confirmatory factor analysis of ABCD neurocognitive battery data.

What this study cannot tell us

Only European-ancestry children were included, limiting generalizability. Cross-sectional design at one age point. Polygenic scores explain only a small fraction of variance. The findings reflect genetic associations, not the effects of cannabis use itself.

How to read the evidence

Moderate: large well-characterized sample from ABCD study with rigorous methods, but cross-sectional and limited to one ancestry group.

When this study was published

Published in 2022.

The bigger picture

This study highlights the complexity of genetic research in substance use. The same genetic variants that predict trying cannabis also predict higher cognitive ability, possibly through shared associations with socioeconomic advantage or personality traits like openness. This finding cautions against simplistic interpretations of substance-use genetics.

Questions still open

Will these children with higher cannabis polygenic risk actually use cannabis as adolescents? If so, will the positive cognitive association reverse due to actual cannabis exposure? Does openness to experience mediate the genetic-cognitive link?

Common questions

Does this mean cannabis makes you smarter?

No. These children had never used cannabis or any other substance. The finding means that genetic variants associated with trying cannabis also happen to be associated with higher cognitive ability, likely through shared traits like curiosity, openness, or socioeconomic factors.

Why would genes for cannabis use be linked to intelligence?

Genome-wide studies of "ever tried cannabis" capture genes related to opportunity and personality (curiosity, openness to experience, socioeconomic access) alongside addiction-specific biology. The cognitive link likely reflects these broader traits rather than anything specific to cannabis.

Read the original research

Associations between cognition and polygenic liability to substance involvement in middle childhood: Results from the ABCD study.

Drug and alcohol dependence, 232, 109277

View on PubMed ↗Publisher’s paper ↗

Citation

Paul, Sarah E; Hatoum, Alexander S; Barch, Deanna M; Thompson, Wesley K; Agrawal, Arpana; Bogdan, Ryan; Johnson, Emma C. (2022). Associations between cognition and polygenic liability to substance involvement in middle childhood: Results from the ABCD study.. Drug and alcohol dependence, 232, 109277. https://doi.org/10.1016/j.drugalcdep.2022.109277