Adolescents who drink alcohol are at increased risk for injury and substance use disorder later in life, even when they do not meet criteria for alcohol use disorder (AUD). This study assessed changes in grey matter volumes over a 10-year period between adolescence and early adulthood in individuals who had alcohol use (as defined by AUDIT-C score), but did not meet criteria for AUD or use other substances.

• The following areas had smaller grey matter volumes in participants with “heavy” drinking when compared with those with “light” consumption* (control): bilateral subgenual anterior cingulate cortex, right orbitofrontal and frontopolar cortex, right superior temporal gyrus, and the right insular cortex.

* Defined by authors as: heavy = AUDIT-C score of ≥4 for males or ≥3 for females; light = AUDIT-C score of ≤2.
Comments: This study demonstrates that even levels of alcohol consumption that may be considered benign “experimentation” during adolescence are associated with smaller grey matter in several brain regions. Functional changes in the insular cortex are associated with propensity to return to substance use; disrupted development in this area may be the basis of the association between early initiation and increased risk of AUD in adulthood. The results underscore the risks of adolescent alcohol use and suggest that AUD diagnostic criteria may not be sensitive enough to identify them in this population.
Sharon Levy, MD, MPH
Reference: Heikkinen N, Niskanen E, Könönen M, et al. Alcohol consumption during adolescence is associated with reduced grey matter volumes. Addiction. 2017;112(4):604–613.