A genetic risk for marijuana dependence may be associated with a higher inherited risk for major depression, according to a new study.
Researchers analyzed the gene profiles of more than 14,000 people and identified several genetic variants that significantly boost the risk of marijuana dependence. According to the researchers, it’s the first study to pinpoint those variants.
The investigators also examined whether people with some forms of mental illness might also be at higher risk for marijuana dependence, as they are for alcohol and other substances.
“We were surprised to find a genetic risk overlap between cannabis dependence and major depression,” said study senior author Dr. Joel Gelernter, a professor of psychiatry, genetics and of neuroscience at Yale University, in New Haven, Conn.
The findings might also help explain why many people with schizophrenia have marijuana dependence, he said in a university news release.
The study was published March 30 in the journal JAMA Psychiatry.
The U.S. National Institute on Drug Abuse has more about marijuana.