Researchers Uncover Genetic Factors Influencing Cannabis Use

A groundbreaking study has revealed potential genetic factors that may influence why some individuals use cannabis infrequently while others become frequent users or develop cannabis use disorder. Conducted by Hayley Thorpe, a postdoctoral researcher at the Schulich School of Medicine & Dentistry, and her colleagues at the University of California San Diego School of Medicine, the research was published in the journal Molecular Psychiatry and analyzed data from over 130,000 individuals.

The research marks a significant step in understanding the complex interplay between genetics and cannabis use. Thorpe and her team found that cannabis use is influenced not by a single gene, but by a combination of genetic factors. “Our study is specifically focused on the genetics of cannabis use and what relationships these genetics have with health,” noted Thorpe. She emphasized that the patterns of cannabis usage are crucial to understanding health outcomes related to its consumption.

The study highlights an urgent need for clinical treatments to address cannabis use disorder, which affects up to 27 percent of individuals who have tried cannabis. Despite this prevalence, there are currently no pharmacological treatment options available. Thorpe hopes that identifying the genetic pathways associated with cannabis use may pave the way for innovative interventions.

Key Genetic Factors Identified

Researchers employed a method known as genome-wide association study (GWAS), which scans the entire genome for common genetic variants linked to specific traits. The study focused on two main traits: lifetime cannabis use and the frequency of use. Thorpe’s team identified significant genetic variations in two genes: CADM2 and GRM3.

Previous studies have associated CADM2 with impulsivity and risk-taking behavior, but this study marks the first time it has been linked to the frequency of cannabis use. The gene GRM3 also emerged as a significant factor, although it had not been previously connected to cannabis use in prior research.

By differentiating between individuals who use cannabis infrequently and those who use it frequently, the researchers were able to delve deeper into the genetics of pre-addiction behaviors. “Our study is the first to use GWAS to examine any of the intermediary stages of cannabis use through frequency of use,” Thorpe explained. This approach allows for a better understanding of the biological and health associations tied to regular, yet non-pathological, cannabis use.

Implications for Public Health and Stigma Reduction

While acknowledging that genetics play a role, Thorpe stressed that they are not the sole determinant of an individual’s relationship with cannabis. She pointed out that environmental factors and personal habits are equally significant in shaping health outcomes. “First and foremost, we hope everyone understands that genetics are not the sole determinant of one’s destiny,” Thorpe stated.

Understanding the genetic underpinnings of cannabis use could help in developing targeted treatments for cannabis use disorder and contribute to reducing the stigma associated with substance use. Thorpe articulated, “When we understand the genetics of cannabis use, we can delve deeper into the biological mechanisms underpinning the effects of its use, which can lead to new therapeutic interventions.”

The findings of this study underscore the complexity of cannabis consumption, which varies significantly from person to person. Thorpe and her team aim to further investigate additional cannabis-related traits, including withdrawal symptoms and cravings, to enhance public health strategies.

Ultimately, the research is not just about decoding DNA; it seeks to foster a comprehensive understanding of cannabis use that could inform public health initiatives and ultimately improve lives.