Gene found that may increase risk of cannabis abuse

Out of all illicit psychoactive substances, cannabis is the most frequently used worldwide. As is the case with other forms of addition, cannabis use disorder (CUD) develops by frequent and harmful use of cannabis. A new report from the Danish psychiatric project, iPSYCH, found that a specific gene is associated with an increased risk of cannabis abuse. 

The researchers of the study, whose findings were published in Nature Neuroscience, found that people with CUD are more likely to have variations in their CHRNA2 gene, and this variation affects how much of a specific nicotine receptor is formed. In people who have low levels of this receptor in the brain, there is a greater risk of cannabis abuse.

Associate Professor Ditte Demontis from Aarhus University in Denmark and her colleagues, including scientists from Iceland and the US, tapped into the complete genome of more than 2 000 cannabis users against the genome of 50 000 subjects who it was assumed did not have the condition. CHRNA2 was found in the former subjects. The process was repeated in an analysis of a further 5 500 cannabis users against more than 300 000 non-cannabis users, and produced the same results.

Although it was previously known that substance abuse is the result of environmental and genetic factors, until now the specific genetic factors had not been identified. However, the researchers pointed out that having the gene does not automatically turn people into pot smokers – it simply makes them more likely to become addicted to it, if they start using it. 

Cannabis use worldwide

ScienceDaily notes that cannabis is the most commonly used illegal drug in both Denmark and internationally, and that around one in 10 users becomes addicted to the drug. The South African Society of Psychiatrists (SASOP) is reportedly concerned that there is a growing public perception of cannabis as a "harmless" plant.

Marna Acker, an occupational therapist at Akeso Clinic Nelspruit, explained that although cannabis seems to be a drug that adolescents enjoy experimenting with, use of this popular drug could lead to poor attention span, memory and hearing loss, poor cognitive impairment, and cardiac and lung impairment. In severe cases, cannabis-induced psychosis may occur.

Another frightening statistic is that drug consumption in South Africa is estimated to be twice the world norm. According to EWN, one in six people starts using the psychoactive drug when they reach adolescence, while Emily Feinstein, executive vice president for the Center on Addiction said last year that when teens and young adults use cannabis, they are almost twice as likely to become addicted as adults. The findings of the iPSYCH study could provide valuable information about people who end up developing CUD.

iPSYCH study ‘first of its kind’

The study is the first of its kind on this scale and Demontis highlighted the need to direct more research towards understanding the nature of addiction, and to determine whether other genes also impact cannabis addiction.

“Our hope is to be able to improve treatment and perhaps in the long-term even prevent this abuse,” she said.