Danish researchers have discovered a gene that raises the risk of marijuana addiction. The research encompassed studying thousands of people to uncover a potential genetic cause of cannabis-use disorders.

The research discovered that people with cannabis-use disorders were more likely to have variants in their CHRNA2 gene, a gene which they say regulates nicotinic acetylcholine receptors in the brain. These receptors respond to both drugs and the chemical messengers that travel between nerve cells and are also active among tobacco users.

The study, published in the journal Nature Neuroscience, shows that Cannabis-use disorder (CUD), has a ‘strong genetic component,’ the researchers from Aarhus University wrote. In turn, this may pave the way to preventing CUD in future generations.

How the Study Worked

Researchers entered the study intending to see if DNA is responsible for chronic marijuana use and addiction. To create their findings, the researchers analyzed the genes of 2,387 people diagnosed with cannabis addiction throughout Denmark. The researchers compared the user’s genomes to the genes of 48,985 people who do not use marijuana to create their initial findings. The study was then repeated, testing 5,501 users and 301,041 ‘controls.’

Researchers also compared their findings investigations into how DNA impacts thinking skills. They discovered that people with a higher number of variants for the DNA that regulates cognition are more likely to use cannabis.  Study author Dr. Ditte Demontis says of the results, “We need to undertake even more research into how the genetic differences in the genome contribute to the development of cannabis abuse.” He admits that further research will be required. “…We need to map out the precise biological mechanisms that lead to one person having a higher risk of becoming a substance abuser than another.”

About Cannabis Use Disorder

About 9% of all marijuana users become dependent on it and develop and marijuana use disorder, according to the National Institute on Drug Abuse. As of 2015, about four million people in the United States met the diagnostic criteria for a marijuana use disorder, and nearly 138,000 marijuana users voluntarily sought treatment for their marijuana use.