Genetic Insights Into Cannabis Use and Associated Health Risks

A study was conducted by the University of California, San Diego, of Medicine over 130,000 participants. In collaboration with the genetic testing company 23 and Me. It reveals genes linked to cannabis use and mental health issues. Two key genes, CADM2 and GRM3, have been identified as having an association with brain signalling and impulsivity. There is a broader health impact of cannabis use with respect to genetic predisposition. Over 100 traits of physical, cognitive, and psychiatric are found to be linked.  The study also reviews the relationship between genetics and traits that contribute to the development of cannabis use disorder. This interferes with daily life as well. Currently, there is no FDA-approved drug treatment for cannabis use disorder.

Read More: Genes and Human Behaviour: How DNA Shapes Emotions, Intelligence, and Resilience

Genetics and Cannabis Use 

Genome-wide association study (GWAS) was conducted on over 131,895 23andMe research participants. The goal was to understand the relationship between genetic data and cannabis use. A survey was circulated among participants, which had questions on have they had ever used cannabis; those who answered yes were asked about the frequency. These research studies help in identifying the molecular system that links brain functioning to cannabis use. 

• Two key genes: Two genes have been found to have an association with frequent use of cannabis: Cell Adhesion Molecule 2 (CADM2) and Metabotropic Glutamate Receptor 3 (GRM3), according to the study. CADM2 is involved in signalling between nerve cells, especially in synapse formation and cell assembly. The gene has also been linked to various conditions and traits such as obesity, cancer metastasis, and impulsive personality. GRM3 is identified as a communicator between neurons and long-term brain plasticity. It has also been associated with psychiatric disorders such as bipolar disorder, schizophrenia, etc. 
• New Gene Association: 40 additional genes were found to be associated with the use and frequency of cannabis use through secondary analysis. 29 of them have never been linked to genes and cannabis use previously. 

Cannabis use & Health conditions 

To understand the association between frequent cannabis use and its impact on health, along with genetic predisposition, two large independent studies were analysed by researchers. These were from the National Institutes of Health’s (NIH) All of Us Research Program and Vanderbilt University Medical Centre’s biobank. The result identified more than 100 different traits, including psychiatric disorders (depression, anxiety, schizophrenia, etc), cognitive traits (risk taking, executive functioning), and physical health (chronic pain, diabetes, etc). Also associated with high risk of tobacco use and infectious diseases such as HIV, viral hepatitis, etc. 

Read More: Psilocybin as a Neuromodulator: A Study on Its Role in Pain related Depression and Chronic Pain 

Researchers View 

Sandra Sanchez-Roige, PhD, associate professor of psychiatry at UC San Diego School of Medicine and senior author of the study, shared that although cannabis is widely used among people but its impact on health is not well-researched. Sanchez-Roige claims that nearly 30% of individuals develop cannabis use disorder out of the people who try cannabis. According to Abraham A. Palmer, PhD, professor and vice chair for basic research in the department of psychiatry at UC San Diego School of Medicine and co-author of the study, the association of genetics with people who would try drugs, and who are at risk of developing an addiction, is well known. 

Application of Research 

A preventive strategy could be formed that is customised to predict and prevent the use of cannabis. Early-stage risk could be detected with this understanding of genetics. The study was published in Molecular Psychiatry on 13th October 2025.