Large Study Explores Cannabis Use Disorder and its Complex Genetic Links to Mental and Physical Health

A study published November 20, 2023 in the journal Nature Genetics closely examined the links between genetics and cannabis use disorder (CanUD). The study titled “Multi-ancestry genome-wide association study of cannabis use disorder yields insight into disease biology and public health implications,” cited a need to better understand the risk factors for CanUD as more US states and countries are increasingly allowing for cannabis use for medical and recreational purposes (1).

Researchers from Yale University and the Department of Veterans Affairs studied genotype data from over a million individuals around the world and from a wide array of ancestry, sourced from genetic databases such as the Million Veteran Program (MVP) (1,2,3). One finding from the study was the discovery of genetic markers specific to ancestry that indicated a risk of CanUD (1,4). Another finding was a bidirectional relationship—when two conditions can influence each other— between CanUD and schizophrenia, and a unidirectional causal effect of chronic pain on CanUD (1,3).

"Our research represents a significant step forward in our understanding of genetic architecture underlying cannabis use disorders, their relationship to psychopathology, and their potential health consequences,” stated Daniel Levey, PhD, one of the authors of the study (2). “For example, we were able to compare self-reported cannabis use to diagnosed cannabis use disorder. We found diagnosed cannabis use disorders are positively associated with symptoms of post-traumatic stress disorder, while cannabis use was not. Schizophrenia on the other hand was found to be positively associated with both cannabis use and cannabis use disorder. "

The study also noted the possibility of a connection between CanUD and lung cancer. “A genetically informed causal relationship analysis indicated a possible effect of genetic liability for CanUD on lung cancer risk, suggesting potential unanticipated future medical and psychiatric public health consequences that require further study to disentangle from other known risk factors such as cigarette smoking,” stated the abstract (1).

According to another of the study’s authors, Joel Gelertner, MD, the study was “the largest genome-wide study of cannabis use disorder ever conducted” (5).

References

1. Levey, D. F.; Galimberti, M.; Deak, J. D.; Wendt, F. R.; Bhattacharya, A.; Koller, D.; Harrington, K. M.; Quaden, R.; Johnson, E. C.; Gupta, P.; et al. Multi-ancestry genome-wide association study of cannabis use disorder yields insight into disease biology and Public Health Implications. Nature Genetics 2023 DOI: 10.1038/s41588-023-01563-z.
2. Gardner, C. Multi-ancestry genome-wide association study of cannabis use disorder yields insight into disease biology and Public Health Implications https://medicine.yale.edu/news-article/multi-ancestry-genome-wide-association-study-of-cannabis-use-disorder-yields-insight-into-disease-biology-and-public-health-implications/. (accessed Nov 22, 2023).
3. Tozer, L. Massive genetic study finds genes linked to cannabis addiction https://www.nature.com/articles/d41586-023-03629-8 (accessed Nov 22, 2023).
4. Sabaghi, D. Study finds genetic link to cannabis use disorder https://www.forbes.com/sites/dariosabaghi/2023/11/21/study-finds-genetic-link-to-cannabis-use-disorder/?sh=11a20feb3925 (accessed Nov 22, 2023).
5. Hathaway, B. Genomic study links cannabis abuse to multiple health problems https://news.yale.edu/2023/11/20/genomic-study-links-cannabis-abuse-multiple-health-problems (accessed Nov 22, 2023).