Alcohol Hurts Brain Development in Teenagers
Moderate and heavy drinkers had faster gray-matter decreases and slower white-matter increases than nonimbibers at 2-year follow-up, and increasing intake worsened outcomes progressively.
Researchers studying altered brain development in adolescent drinkers have not tested dose effects because study designs did not include a moderate-intake group. These investigators analyzed data from a multisite 2-year magnetic resonance imaging study involving 483 young people (baseline age range, 12–21; 50% males).
At baseline, all participants were nondrinkers or low drinkers; at follow-up, 65 had become moderate drinkers, and 62 had become heavy drinkers. From baseline to 2-year follow-up, heavy users had accelerated decreases in gray matter and slower increases in white matter, compared with the trajectories in no/low drinkers. In analyses controlling for sex, age, sex-by-age interactions, and multiple comparisons, gray-matter decreases in frontal, cingulate, and total cortex were significantly accelerated in heavy drinkers, and white-matter increases in central white matter were slower. Controlling for supratentorial volume, marijuana use, and family histories of alcoholism did not affect the results. However, among the 21 heavy drinkers, family alcoholism history was associated with steeper slopes. Trajectories in the moderate-drinking group did not significantly differ from those in the no/low and heavy groups, but fell in between, consistent with a dose effect. Participants who became heavy drinkers were older than the others; in comparisons of age-matched heavy and no/low drinkers, no significant differences were seen.
These findings, and those on cognitive deficits (NEJM JW Psychiatry Jan 2018 and Alcohol Clin Exp Res 2017 Oct 30) support instituting public health programs geared to limiting adolescent drinking by publicizing the resultant brain damage, similar to efforts aimed at prenatal alcohol consumption. Keeping kegs out of dormitories would be very helpful. Early interventions for known risk factors for alcohol use, such as attention-deficit/hyperactivity and bipolar disorders, are indicated. Also, practitioners can educate families about alcohol's deleterious effects and counsel offspring of parents with alcohol use disorders about the heightened familial risk.