The large study finding genetic associations between cannabis use and various traits has applications for cannabis use disorders.
Researchers at UC San Diego School of Medicine, in collaboration with genetic testing company 23andMe, have identified regions of the human genome associated with cannabis use, linking use to psychiatric, cognitive and physical health in ways that may inform prevention and treatment of cannabis use disorder.
The long-term effects of cannabis on health are “poorly characterized,” study senior author and UCSD School of Medicine professor of psychiatry Sandra Sanchez-Roige, PhD, said in a press release.
Nearly 30% of those who try cannabis will go on to develop cannabis use disorder.
“Understanding the genetics of early-stage behaviors may help clarify who is at greater risk, opening the door to prevention and intervention strategies,” Sanchez-Roige said.
The findings, published Oct 13 in Molecular Psychiatry, resulted from a genome-wide association study (GWAS) analyzing relationships between cannabis use and genetic data provided by 131,895 23andMe research participants.
The study found that lifetime cannabis use was associated with two genes. The first was Cell Adhesion Molecule 2 (CADM2), a gene involved in cell assembly and in signaling between nerve cells, particularly in the brain. Previous studies have linked CADM2 to various traits and conditions, including impulsive personality, obesity and cancer metastasis.
The second gene was Metabotropic Glutamate Receptor 3 (GRM3), which is involved in communication between neurons and long-term brain plasticity. GRM3 has already been linked to psychiatric disorders, including schizophrenia and bipolar disorder.
A secondary analysis revealed an additional 40 genes associated with lifetime cannabis use and four genes associated with frequency of cannabis use, 29 of which had not previously been associated with cannabis-related traits.
“We showed that the genetics of cannabis use — both trying it and using it more often — are tied to the genetics of other psychiatric traits, cognitive measures and even physical health problems,” said Sanchez-Roige.
Analyzing which health conditions were correlated with a genetic predisposition for cannabis use, the researchers then found lifetime cannabis use and frequency of cannabis use were genetically correlated with more than 100 different traits including psychiatric conditions like schizophrenia, ADHD anxiety and depression; cognitive traits like executive function and risk-taking; and physical health like diabetes, chronic pain and coronary artery disease.
While there are currently no FDA-approved drug therapies to treat cannabis use disorder, the study authors hope their discoveries will lead to efforts in prevention and treatment.
