Marijuana and the Brain

Study: Adolescent Cannabis Exposure Not Associated With Structural Brain Differences in Adulthood

The use of cannabis during adolescence is not associated with structural brain differences in adulthood, according to longitudinal data published in the journal Drug and Alcohol Dependence. Researchers concluded, “[T]he patterns of cannabis use typically seen in community-dwelling adolescents does not appear to have lasting effects on brain structure.”

Marijuana and the Brain

Yet Another Study Finds That Cannabis Use Is Not Independently Linked With IQ Decline

Cannabis use by teens is not independently linked with adverse changes in intelligence quotient or executive functioning, according to longitudinal data published online ahead of print in the journal Addiction. Investigators concluded, “Short-term cannabis use in adolescence does not appear to cause IQ decline or impair executive functions, even when cannabis use reaches the level of dependence.”

Marijuana Brain

Twin Study: Marijuana Use Has No Direct Effect On IQ

The cumulative use of cannabis by adolescents has no direct effect on intelligence decline, according to longitudinal data published today in the Proceedings of the National Academy of Sciences. Investigators concluded: “In the largest longitudinal examination of marijuana use and IQ change, … we find little evidence to suggest that adolescent marijuana use has a direct effect on intellectual decline.”

Marijuana Graduate

Study: Cannabis Use Not Predictive Of Lower IQ, Poorer Educational Performance

Marijuana use by adolescents is not associated with lower IQ or poorer educational performance once adjustments are made for potential confounders, specifically cigarette smoking, according to longitudinal data published online ahead of print in the Journal of Psychopharmacology. Researchers concluded, “In summary, the notion that cannabis use itself is causally related to lower IQ and poorer educational performance was not supported in this large teenage sample.”