Cannabis Use and Cognitive Functioning Across the Lifespan

Purpose of Review: To examine the acute and long-term effects of cannabis use on cognitive functioning across the lifespan, and to evaluate the evidence for the hypothesis of developmental sensitivity to cannabis effects. Recent Findings: Acute cannabis intoxication impairs cognitive functioning, and frequent cannabis use is associated with subtle cognitive deficits after intoxication has passed, in adolescence, young adulthood, and midlife. Longitudinal studies show that more frequent and longer-term cannabis use are associated with cognitive decline, though associations are small and inconsistent in studies of adolescents and young adults and small-moderate in studies of longer-term use to midlife. Older adults are understudied. Findings on prenatal and early postnatal cannabis exposure and cognitive functioning, though mixed, caution against use during pregnancy. Summary: It seems likely that cannabis use is associated with cognitive deficits across the lifespan. However, the very young and the old are understudied, and there are few within-study comparisons of age differences in cognitive effects. The evidence on age-related differences in sensitivity to cannabis effects on cognitive functioning in humans is inconclusive.