June 19, 2019
An international research team believes it has identified a gene that makes people more susceptible to cannabis addiction.
People with cannabis use disorders are more likely to have variations in their CHRNA2 gene, a receptor also known to increase the risk of nicotine addiction, according to a new study. Low levels of the receptor are associated with an increased risk of cannabis addiction.
About 9 percent of cannabis users become dependent, according to previous research cited in the study. Cannabis addiction increases the risk of psychosis, bipolar disorder, anxiety disorder and cognitive impairment.
The gene makes people more likely to become addicted if they begin using cannabis, researchers said. It does not make them more likely to become users.
Researchers do not know how CHRNA2 increases the risk of addiction and additional research is needed to determine whether other genes also impact cannabis addiction.
To isolate the gene, researchers compared the genomes of 2,387 Danish people known to have cannabis use disorder with a control group of 48,985 people. They then replicated the findings by comparing the genomes of 5,501 people with CUD from an Icelandic database and a control group of 301,041 people.
The study was led by researchers from Aarhus University in Denmark, but also included scientists from the Iceland and the United States. Their findings were published Monday in Nature Neuroscience.