Ever wondered why you maintained your weed-smoking hobby, but some of your associates did not?

Well, you could be about to find out the reasons behind your relationship with the plant, thanks to a  study published in the journal Nature Neuroscience. This is the largest genome-wide association study (GWAS) for lifetime cannabis use to date. 

It was co-led by Eske Derks from the QIMR Berghofer Translational Neurogenomics Laboratory in Brisbane, in cooperation with researchers from the Netherlands and the U.S.

Researchers gathered data from a total of 180,000 study subjects to ascertain an association between a person’s genetics and their relationship with weed. Data was gleaned from the participants of 16 separate studies, as well as from the users of DNA-testing ancestry company 23andMe.

Interestingly, the likelihood of a person favoring cannabis is determined by 35 different genes.

Study findings reveal a “genetic overlap” between cannabis use and personality traits  

This cannabis study discovered that individuals who are prone to developing ADHD and schizophrenia are more liable to “lifetime cannabis use.”

“We examined millions of genetic variants and identified 35 genes that influence whether a person is likely to use cannabis during their lifetime,” Derks explained. “Together, the genetic variants we examined account for one-quarter of the genetic or inherited influence on cannabis use. Of course, there are also social and environmental factors that contribute to whether a person will use cannabis.”

Another interesting discovery was the link between cannabis consumption, personality traits, and alternative habits. Genetics were proven to influence these things.

“The study found a genetic overlap between cannabis use and the use of tobacco and alcohol,” the authors wrote in a press release. “There was a similar overlap between cannabis use and personality types that were prone to more risky behavior or were more extroverted.”

“Genetic variants impacting cannabis use partially impact other psychological or psychiatric features as well.”

Genetics do seem to play an important role in a person’s relationship with weed, but genes are not the absolute determining factor for an individual’s probability of using the plant. The authors of this cannabis study stated that a person’s genetics “helped to explain approximately 11 percent of the differences in cannabis use between people,” which, let’s be honest, isn’t a very big percentage.

People with genetic risk for schizophrenia prefer to self-medicate with weed

Something rather intriguing was gleaned from this cannabis study. The findings indicated that individuals who are genetically at risk for schizophrenia may decide to keep their symptoms under control by self-medicating with cannabis.

Conversely, previous studies have come to the conclusion that cannabis consumption may potentially trigger schizophrenia or exasperate the symptoms.

A separate study published during the second week of August argued that the psychoactive cannabinoid THC (tetrahydrocannabinol) could actually be the compound that provokes mental illness. Researchers concluded that THC’s non-psychoactive cousin, CBD (cannabidiol), could potentially treat patients with schizophrenia.

Authors of the cannabis study, which was published in Nature Neuroscience, added that the relationship between cannabis consumption and schizophrenia is nuanced and complex. They did not manage to debunk the myths that cannabis causes or worsens schizophrenia.