Revision History

A landmark study tracking 11,036 U.S. adolescents from ages 9 to 17 found that teens who used cannabis showed slower gains in memory, attention, language, and processing speed compared to non-using peers — with THC identified as the likely driver. But the effects were modest, the study is observational, and prior meta-analyses suggest cognitive deficits may largely reverse after sustained abstinence, raising questions about whether the findings reflect lasting harm or temporary impairment.