Recent research undertaken by a distinguished group of scientists has unveiled significant findings concerning the long-term implications of marijuana use on cognitive performance into middle age. The study, spearheaded by Auer R, Vittinghoff E, Yaffe K, et al., meticulously analysed data gleaned from the Coronary Artery Risk Development in Young Adults (CARDIA) study. This cohort study followed 5115 black and white men and women who were aged between 18 to 30 years at the outset, tracking their health outcomes over several decades.

The Verbal Memory Dilemma

A critical discovery of this research is the clear, dose-dependent relationship between cumulative lifetime marijuana use and a decline in verbal memory performance observed in individuals during their middle years. Specifically, for every five years of marijuana use, participants demonstrated a reduction of 0.13 standardised units in their verbal memory scores. This particular aspect of cognitive function appears to be especially susceptible to the effects of sustained marijuana consumption, raising concerns about the potential long-term cognitive consequences associated with its use.

Implications for Public Health and Awareness

The findings from this study underscore the necessity for increased public education and awareness regarding the potential cognitive risks linked to prolonged marijuana use. While the research did not find significant associations between marijuana exposure and other areas of cognitive function, such as executive function or processing speed, the impact on verbal memory alone warrants attention. These insights contribute to a growing body of evidence suggesting that early and regular use of marijuana could have enduring adverse effects on cognitive health. Such research is paramount in guiding public health policies and fostering a community informed about the implications of marijuana use on long-term mental well-being.

Published in JAMA Internal Medicine.