Meta-study: No evidence that adolescent cannabis use reduces brain volume

This study examined 16 qualified, cross-sectional, published studies that included 830 young adults aged 14 to 26 to determine if there was any correlation between adolescent cannabis use and global (GBV) or regional brain volume. It was published in the journal Cannabis and Cannabinoid Research in April 2022.

386 of the participants were cannabis users who started cannabis use between ages 15-19. 444 were not cannabis users (control).

  • "We found no detectable group differences in any of the GBVs (intracranium, total brain, total white matter, and total gray matter) and regional brain volumes (i.e., hippocampus, amygdala, orbitofrontal cortex, and total cerebellum)"
  • "this early evidence suggests nonsignificant volume differences between young cannabis users and nonusers"

Note that this study only looked at brain volume, and not brain function. However, some previous studies have concluded that early cannabis use was correlated with reduced brain volume. This study did not find evidence for that conclusion.

The full text article is here at