• Posted May 23, 2023

'Complex' Genetic Links Between Marijuana Use, Psychiatric Ills

A subset of people may be at high risk for both psychiatric disorders and for using marijuana, based on their genetics, according to a new study.

Researchers from the University of Oslo in Norway have found that some of the genetic variants associated with cannabis use are also linked to psychiatric disorders.

"These findings are important as they show that the complex links between cannabis use and these disorders may not only be caused by cannabis use itself, but could also be driven by shared genetic susceptibility,"lead co-author Nadine Parker said in a university news release.

The rate of cannabis use is high among patients with disorders linked to psychosis, including schizophrenia and bipolar disorder. Cannabis is a psychoactive drug that can sometimes produces psychotic-like symptoms, according to the study.

"This study shows that there is a shared genetic basis underlying our susceptibility to both cannabis use and certain psychiatric disorders,"lead co-author Weiqiu Cheng said in the release.

To study this, Parker, Cheng and their colleagues used advanced statistical modeling. They found that a majority of shared variants increased the risk of both cannabis use and developing either schizophrenia or bipolar disorder. Yet, there were some genetic variants with opposing effects that increased the risk of cannabis use while decreasing the risk of the two psychiatric disorders.

In some parts of the world, cannabis is used medicinally to relieve pain or as an antidepressant, the authors noted. One component of the drug is being considered as a potential treatment for psychosis.

"Shared genetic variants with opposing effects may suggest the presence of biological mechanisms that could support the beneficial effects of cannabis,"the researchers said.

These results may lead to personalized care, including preventative and interventional measures for high-risk individuals, the authors said. It could include reducing cannabis use among individuals at high genetic risk for schizophrenia and bipolar disorder and stratifying patients for more specialized treatment plans.

Future studies investigating the biological effects of the shared genetic variants could contribute to the development of more targeted treatment efforts, the authors said.

The findings were published in the June issue of the journal Lancet Psychiatry.

More information

The U.S. National Institute on Drug Abuse has more on cannabis and psychiatric disorders.

SOURCE: University of Oslo, news release, May 19, 2023