Normal brain maturation is characterized as increasing in cortical gray matter volume through the first decade, followed by continuous decline thereafter. Concurrently with gray matter decline, supratentorial white matter continues to grow throughout adolescence, and slows during the third decade of life. Given that adolescence is a time of risk-taking and exploration, a likely prediction is that excessive alcohol use may result in accelerated gray matter loss, attenuated white matter growth, or both. A recent study examined 483 adolescents (age 12-21) prior to initiation of drinking, and 1 and 2 years later. At the 2-year assessment, 356 participants were in the no/low alcohol consumption category, 65 had initiated moderate drinking, and 62 were heavy drinkers. In no/low drinkers, gray matter volume declined throughout adolescence and slowed in many regions in later adolescence. White matter regions grew at faster rates at younger ages and slowed toward adulthood. Those who initiated heavy drinking demonstrated an accelerated gray matter trajectory, significantly different from the norm. Specifically, reductions in the superior frontal and the posterior cingulate cortices were observed. Initiation of drinking during adolescence, a vulnerable period of brain development may result in disordered brain growth trajectories.
>>Pfefferbaum A, Kwon D, Brumback T, et al. Altered Brain Developmental Trajectories in Adolescents After Initiating Drinking. Am J Psychiatry. 2017;:appiajp201717040469. Abstract