KEY POINTS

  • Study: THC affects adolescent human females more than males
  • The brain is highly sensitive to the risk of initiating cannabis during adolescence
  • The findings can help identify people at risk of cannabis dependence 

THC (Tetrahydrocannabinol), the main psychoactive ingredient of cannabis affects females differently than males, according to a new study.

The study, done by the Weill Cornell Medical College has found that because of a common variation in the human genome, adolescent females are increasingly susceptible to cannabis. Cannabis affects the brain’s reward processing circuit, according to the study, which was done on adolescent female mice.

"Our study shows that a variant in the FAAH gene, which is found in about one-third of people, increases vulnerability to THC in females and has a large-scale impact on brain regions and pathways responsible for processing reward. Our findings suggest that genetics can be a contributing factor for increased susceptibility to cannabis dependence in select populations,” Dr. Caitlin Burgdorf, a recent doctoral graduate from the Weill Cornell Graduate School of Medical Sciences and the lead author of the study titled, “Endocannabinoid genetic variation enhances vulnerability to THC reward in adolescent female mice,” which was published in the Science Advances Journal Wednesday, told Medical Xpress.

The brain’s endocannabinoid system regulates the activity of cannabinoids and mood. It also regulates the effect of THC. The fatty acid Amide Hydrolase (FAAH) breaks down naturally occurring cannabinoids such as anandamide, which is naturally found in the brain. The study found adolescent female mice, because of a human gen variant they possess, allow FAAH to degrade more easily, which adds to anandamide levels in the brain. Because of this, the mice favored an environment with THC over a neutral environment. The study found that females, generally, were more sensitive to the effect of cannabis which quickly leads to cannabis dependence.

According to the researchers, genetic variations also lead to increased connections between the reward processing areas of the brain.

"We are getting one step closer to understanding exactly how neurodevelopmental and genetic factors play interrelated roles to increase susceptibility for cannabis dependence," Dr. Francis Lee, chair of the Department of Psychiatry at Weill Cornell Medicine and psychiatrist-in-chief at New York-Presbyterian/Weill Cornell Medical Center stated.

The authors also stated that further research could reveal the genetic factors responsible for cannabis addiction.