Budapest, Hungary: Adults who consume moderate amounts of cannabis perform no differently than abstainers on a wide range of cognitive tasks, including tests of executive function and working memory, according to data published in the journal Comprehensive Psychiatry.
An international team of researchers from Hungary, France, and Spain assessed cognitive performance in 122 participants. Forty-three subjects reported no current use of cannabis. Thirty-six subjects were defined as “recreational users,” having used marijuana regularly over the past six months. The remaining 43 subjects were described as “problematic users,” having been classified as suffering from cannabis use disorder (CUD). All study participants performed a battery of cognitive tests, including assessments of executive function, implicit learning capabilities, working memory, and inhibitory control.
Testing revealed no significant differences between recreational users and abstainers. Problematic users also exhibited few overall differences aside from deficits in complex working capacity.
“Our results revealed a specific cognitive signature for cannabis use disorder severity, with the problematic user group showing a selective deficit only in complex working memory capacity compared to non-users. In contrast, performance in other executive domains — including inhibitory control and cognitive flexibility — as well as implicit learning, was preserved across all groups,” investigators reported.
‘This study highlights that cognitive alterations in cannabis users are not uniformly present but instead emerge selectively in relation to addiction severity,” the study’s authors concluded. “Our findings suggest that problematic use is marked not by broad cognitive impairments, but by a selective deficit in complex working memory capacity. At the same time, other executive functions and implicit learning processes appeared largely preserved, challenging the view of a global cognitive decline in problematic use.”
The researchers’ findings are consistent with those of other studies reporting that the modest use of cannabis has little if any significant adverse effects on overall cognitive performance.
Full text of the study, “Dissociating the cognitive underpinnings of recreational cannabis use from problematic use,” appears in Comprehensive Psychiatry. Additional information is available from the NORML Fact Sheet, ‘Marijuana Exposure and Cognitive Performance.’