The Association Between Marijuana and Schizophrenia


According to a new study, there is a link to smoking marijuana and schizophrenia.

The study was conducted by researchers from Radbound University in the Netherlands and more than 180,000 people were part of the study.

Researchers discovered that people with schizophrenia are more likely to use marijuana.

The large-scale genetic study was published in Nature Neuroscience, on Monday, Aug. 28, 2018. It was conducted by a team of scientists who are part of the International Cannabis Consortium.

The reason this study was conducted was, so scientists may better understand genetic variations that increase people’s likelihood of using marijuana.

Scientists claim this genetic study is the largest to date on the use of marijuana. The study included data from the U.K. Biobank, association results from DNA testing kit 23andMe volunteers, and data from individuals in 16 other smaller studies.

The study was able to identify 35 genes in 16 different sections across the genome associated with cannabis use and schizophrenia. The strongest associations were in a gene called CADM2.

CADM2 was already associated with risky behavior, alcohol use, and personality, according to professor Jacqueline Vink, lead author of the study.

During this study, Vink and her team were able to examine across over a million genetic variants. Researchers discovered eight variations in human DNA, known as single-nucleotide polymorphisms, associated with marijuana use. These variants explained 11 percent of the differences in marijuana use between people choosing to use.

One of the largest correlations was the genetic overlap between marijuana use and the risk of schizophrenia.

The results were not a surprise to scientists, because previous studies have already shown that the use of marijuana is associatied with schizophrenia. “However, we also studied whether this association is casual. Our study showed that people with a vulnerability to develop schizophrenia are at increased risk of using cannabis,” according to Vink.

Researchers for this study used an analysis technique called “Mendelian randomization” to show the casual relationship between the increased risk of marijuana use and schizophrenia.

According to scientists, this indicates people with schizophrenia use marijuana to self-medicate. However, researchers could not ignore the reverse cause-and-effect relationship. This means that marijuana use could contribute to an increased risk of schizophrenia.

Researchers also found a genetic overlap between marijuana use and the use of tobacco and alcohol.

Additionally, there was a similar overlap between the use of marijuana and personality types that are prone to risky behavior or are more extraverted.

According to researchers, “This means that genetic variants impacting cannabis use partially impact other psychological or psychiatric features as well.”

These new findings mean that people with schizophrenia could use marijuana to improve their condition.

By Jeanette Smith


Mirror: Scientists discover a genetic link between cannabis use and SCHIZOPHRENIA

Image Courtesy of José Javier’s Flickr Page – Creative Commons License