This article is more than 5 years old. Information may no longer be current.
Genetic overlap identified between cannabis use, schizophrenia
Click Here to Manage Email Alerts
Results from a large-scale genetic study showed that some of the same genes linked to cannabis use were also linked to certain psychiatric conditions and personality types.
The study also revealed genetic overlap between cannabis use and schizophrenia risk, according to finding published in Nature Neuroscience.
“Research into genetic factors underlying cannabis use can give important clues about (biological) mechanisms that contribute to individual differences in cannabis use,” Joëlle A. Pasman, MSc, of the Behavioral Science Institute at Radboud University, the Netherlands, told Healio Psychiatry. “Also, the current study can give us an idea about how cannabis use behavior is related to other behaviors and traits, and genetic information even enables us to test causal relationships.”
The researchers reported findings from the largest genome-wide association study for lifetime cannabis use (n=184,765), meta-analyzing results from the International Cannabis Consortium study, and data from the U.K. Biobank and 23andMe customers.
“Genetic research into cannabis use might have important applications in the future,” Pasman said. “If future research can give more and more insight into what genetic factors are important for cannabis use initiation, abuse, dependence, and cessation, this might, in the long term, be used to treat problems related to cannabis use.”
The researchers identified 35 different genes in 16 regions related to cannabis use with the strongest associations observed in the gene CADM2, which has been tied to risky substance use and risk-taking in previous research, according to a press release. Combining all measured genetic variants explained 11% of the variance in cannabis use between people, Pasman and colleagues found. S-PrediXcan analyses also revealed that 21 genes had different expression levels for cannabis users compared with nonusers.
“I think that cannabis use should not be viewed in a vacuum,” Pasman told Healio Psychiatry. “Even if we focused on 'lifetime use' rather than regular use or dependence, we find that it is genetically overlapping with a myriad of psychiatric issues and risk behaviors. So, if someone presents him or herself at the clinic with such issues, it might be important to also ask about their cannabis use, or vice versa.”
Mendelian randomization analysis revealed a causal positive influence of schizophrenia risk on cannabis use, indicating that people at risk for schizophrenia were at higher risk for using cannabis. The investigators also observed significant genetic correlations with 14 tested substance use- and mental health-related traits, including tobacco use, alcohol use, risk-taking and ADHD. These results suggest that genetic variants tied to cannabis use were associated with other psychological or psychiatric features as well, according to the release.
“An important message for clinicians is that genetic vulnerability plays a substantial role in individual differences in substance use and abuse,” Pasman said. “Clinics should seriously consider any invitation to take part in such research, as large clinical samples will continue to be crucial to detect genetic effects. The promise that this kind of research shows for future applications in treatment can only be made true through a large collaborative effort between researchers, practitioners, and patients alike.” – by Savannah Demko
Disclosure: Pasman reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.