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Genetic Variation in THC Metabolism May Increase Risk of Marijuana Addiction

By April 10, 2024No Comments

Genetics can play a significant role in determining an individual’s susceptibility to addiction. Several studies have shown that genetic factors contribute to the likelihood of developing cannabis use disorder (CUD), which is characterized by problematic patterns of marijuana use leading to clinically significant impairment.

A new study, led by Medical University of South Carolina researcher Rachel Tomko, Ph.D., adds to this growing body of research. Tomko analyzed THC-metabolizing enzyme genes in 38 young adults with CUD and 16 young adults with other substance use disorders. Her study suggests that variations in how our bodies metabolize marijuana is essential in understanding our risk of abusing weed and developing CUD.

What is THC Metabolism?

When you smoke, vape, or ingest THC, it enters the bloodstream and travels to various organs, including the liver, where much of its metabolism occurs.

Once metabolized, THC and its metabolites are distributed throughout the body via the bloodstream. They are eventually eliminated from the body through urine and feces. The elimination half-life of THC and its metabolites can vary depending on factors such as frequency of use, dose, and individual metabolism.

Individual genetic variations in the enzymes responsible for THC metabolism can influence how quickly and efficiently THC is broken down in the body. Approximately one in four individuals possess genetic variants that result in slower metabolism of THC, which can impact their sensitivity to the effects of marijuana and their risk of abusing or becoming addicted to weed.

Sex-Specific Differences in THC Metabolism and CUD Risk

Dr. Tomko’s data revealed that not all individuals respond to marijuana in the same manner.

Female participants with CUD were more likely to metabolize THC more slowly. This inefficiency prolongs the effects of weed, potentially increasing the risk of becoming addicted.

Conversely, males with a gene variant for slower THC metabolism reported more negative effects upon initial marijuana use. Although slower metabolizers may experience more negative effects, marijuana’s “high” may incentivize continued use, irrespective of adverse outcomes

Dr. Tomko’s study was limited by its size, and future research is needed to further elucidate genetic risk factors for CUD.

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