Marijuana use associated with worse verbal learning and delayed recall in a sample of young adults.

BACKGROUND

There is concern about the cognitive consequences of marijuana consumption.

AIM: To assess the influence of current and past marijuana use and frequency on verbal learning and memory in a sample of adults aged 21 years old.

MATERIAL AND

METHODS

Marijuana use was assessed using a clinician administered interview in 654 participants (56% females), who reported frequency of use, age of first use and whether its use led to problems in their lives. The CogState International Shopping List was administered to assess learning and memory.

RESULTS

Seventy percent reported ever using marijuana, 46% consuming during the past year and 27% during the past 30 days. The latter scored significantly lower on delayed recall. Current and frequent use were significantly associated with lower accuracy in verbal learning and memory.

CONCLUSIONS

In this cohort of adults aged 21 years old, marijuana use was prevalent and related to worse verbal memory.