According to a new study published in the Journal Neuropsychopharmacology, the main psychotropic component of cannabis, Δ⁹-tetrahydrocannabinol (THC), is differentially processed by the bodies of adolescent female and male rats. The study was headed by Neurobiology and Behavior Assistant Professor Stephen Mahler and included other researchers from UC Irvine and Thomas Jefferson University, Philadelphia. The team’s findings give new insights into the sex-dependent manner in which THC impacts the adolescent brain.

Cannabis is the second most commonly used psychotropic drug in the U.S. with widespread usage among young people, according to the National Institute on Drug Abuse. The use of cannabis in teens and young adults has prompted study into THC’s effects on the brain by many investigators, including Professor Mahler’s team.

In his new study, Professor Mahler and his team utilized a translationally-relevant rat model to investigate THC effects in adolescents of both sexes. They conducted a systematic investigation of THC metabolism and distribution in the brain and blood, and characterized its effects on behavior and activity of brain reward and stress neural networks. The team found marked sex differences in THC metabolism, including a female-specific elevation in a THC bioactive metabolite called 11-OH-THC, which confirmed prior suggestive results from human and animal studies. Additionally, they observed dose-dependent and sex-dependent effects on behavior and neural activity within the brain’s reward and stress networks. These findings may help explain why THC effects differ based on sex, and suggest that the drug may have distinct effects on brain development in adolescent boys and girls.