Genome-Wide Association Study Identifies Genetic Links to Cannabis Use

Researchers from the University of California San Diego School of Medicine, in collaboration with the genetic testing company 23andMe, have conducted a genome-wide association study to identify regions of the human genome associated with cannabis use. The study, published in Molecular Psychiatry, reveals new relationships between genetics and traits that contribute to the development of cannabis use disorder.

The researchers analyzed relationships between cannabis use and genetic data provided by 131,895 23andMe research participants, who answered survey questions about their cannabis use. The study found that lifetime cannabis use was associated with two genes: Cell Adhesion Molecule 2 (CADM2) and Metabotropic Glutamate Receptor 3 (GRM3). CADM2 is involved in cell assembly and signaling between nerve cells, particularly in the brain, and has been linked to various traits and conditions, including impulsive personality, obesity, and cancer metastasis. GRM3 is involved in communication between neurons and long-term brain plasticity and has been linked to psychiatric disorders, including schizophrenia and bipolar disorder.

The study also found that a secondary analysis revealed an additional 40 genes associated with lifetime cannabis use and four genes associated with frequency of cannabis use. Twenty-nine of these genes had not previously been associated with cannabis-related traits. The researchers analyzed which health conditions were correlated with a genetic predisposition for cannabis use and found that lifetime cannabis use and frequency of cannabis use were genetically correlated with over 100 different traits, including psychiatric conditions, cognitive traits, and physical health.

Key Takeaways:

• The study found that two genes, CADM2 and GRM3, are associated with lifetime cannabis use and frequency of cannabis use.
• The study also found that 40 genes are associated with lifetime cannabis use and four genes are associated with frequency of cannabis use.
• Twenty-nine of the associated genes had not previously been associated with cannabis-related traits.
• The study found that lifetime cannabis use and frequency of cannabis use are genetically correlated with over 100 different traits, including psychiatric conditions, cognitive traits, and physical health.
• The study suggests that the genetics of cannabis use are tied to the genetics of other psychiatric traits, cognitive measures, and even physical health problems.
• The study highlights the need for further research into the genetic underpinnings of cannabis use disorder and the development of therapeutic targets and preventative interventions.

Statistics:

• 131,895 23andMe research participants contributed to the study.
• The study analyzed survey questions about cannabis use from participants who had provided genetic data.
• The study found that 30% of people who try cannabis go on to develop cannabis use disorder.
• The study identified 29 genes not previously associated with cannabis-related traits.
• The study found that lifetime cannabis use and frequency of cannabis use are genetically correlated with over 100 different traits.
• The study suggests that the genetics of cannabis use are tied to the genetics of other psychiatric traits, cognitive measures, and even physical health problems.

Sources:

• Sanchez-Roige, S., et al. (2025). Genome-wide association study identifies regions of the human genome associated with cannabis use. Molecular Psychiatry, [insert DOI].
• 23andMe Research Team (2025). Genetic testing and research [insert URL].
• University of California San Diego School of Medicine (2025). Researchers identify genetic links to cannabis use disorder [insert URL].
• National Institutes of Health (2025). All of Us Research Program [insert URL].