Should We Still Call It Dope?

In an era of increasing legitimization of marijuana use, little is known about cognitive effects of ongoing use, especially in adolescents and young adults. These researchers conducted a meta-analysis of 69 studies of 2152 “heavy, frequent, and/or problematic cannabis users” (criteria for which were not stated) and 6575 minimally using controls (mean age, 21; mean age of starting cannabis use, 15).

Marijuana use was associated with decrements in cognitive function, with a small but significant overall effect size. Five of eight domains were significantly affected — learning, speed of information processing, delayed memory, attention, and various facets of executive function. The effect size was almost twice as great in those seeking treatmen…