A study conducted by researchers at Arizona State University has found that adolescent marijuana use may not pose much long-term risk on brain function at all.
Due to be published in the next month’s issue of drug and alcohol dependence, the piece of research “tested associations between prospectively-assessed trajectories of adolescent cannabis use and adult brain structure in a sample of boys followed to adulthood.”
For the study, the researchers analyzed self-reported marijuana use among boys aged 13-19 in Pittsburgh in the year 1980. The 1000 boys examined were then categorized in the following four “adolescent cannabis trajectories”:
- Non-users/infrequent users
- Chronic-relatively frequent users
After a thorough analysis over the years, the researchers noted- “boys in different trajectory groups did not differ in terms of adult brain structure in any subcortical or cortical region of interest.”
Furthermore, a subset of 181 of the boys subsequently underwent structural neuroimaging in adulthood when they were between ages 30-36. That subset was then tested to identify any differences in adult brain structure.
The researchers inferred that adolescent marijuana use had no link with structural brain differences in adulthood.
“Even boys with the highest level of marijuana consumption rate in adolescence showed subcortical brain volumes and cortical brain volumes and thickness in adulthood that were in line to those of boys with almost no exposure to marijuana throughout adolescence.”
You can read the entire study here.