A new study provides evidence of the longitudinal effects of heavy alcohol use on the brain. Participants were a cohort of first-year U.S. college students who were recruited into the Brain and Alcohol Research in College Students (BARCS) study. A representative subsample was classified as either sustained abstinent/light drinkers (n = 55) or sustained heavy drinkers (those who met criteria for binge drinking or alcohol abuse at both time points; n = 84), based on self-report. History of ADHD, family history of alcoholism, and mental illness diagnosis were also assessed at baseline and follow-up. Participants in both groups underwent MRI imaging at baseline and 24 months; volumetric changes in gray matter at these two time points were computed for each participant. Chi-square tests and independent sample t-tests were used to compare demographic variables and covariates between groups. Results showed groups did not differ by age, smoking, family history for alcoholism, or mental illness diagnosis, but groups differed significantly by sex (chi-square = 4.47, p = 0.03). Maps of participants’ volumetric changes in gray matter were analyzed separately by group using a 1-sample t-test. Results indicated significant gray matter volumetric (GMV) loss occurred in both drinking groups; however, this result was expected because of the cortical pruning that typically occurs during late adolescence. GMV loss was significantly greater (p < 0.05) among heavy drinkers than among light drinkers/abstainers. Areas of the brain in which GMV loss was accelerated among heavy drinkers included regions responsible for emotion, memory, and decision-making. The authors detected no group-by-sex or group-by-sex-by-time interactions at the whole brain level.
Take away: College students who reported sustained heavy drinking over a two-year period had significantly greater losses of gray matter than their peers who reported sustained light drinking or no drinking. Areas in which this loss was accelerated included regions responsible for emotion, memory, and decision-making.