Brain volume reductions in adolescent heavy drinkers

• Pre-existing frontal brain volume differences were found in future drinkers.
• Adolescent drinkers showed greater brain volume reduction post-alcohol initiation.
• Volume reduction occurred in subcortical and temporal regions.
• QUARC is a useful tool for quantifying longitudinal brain volume changes.

BackgroundBrain abnormalities in adolescent heavy drinkers may result from alcohol exposure, or stem from pre-existing neural features.MethodsThis longitudinal morphometric study investigated 40 healthy adolescents, ages 12–17 at study entry, half of whom (n = 20) initiated heavy drinking over the 3-year follow-up. Both assessments included high-resolution magnetic resonance imaging. FreeSurfer was used to segment brain volumes, which were measured longitudinally using the newly developed quantitative anatomic regional change analysis (QUARC) tool.ResultsAt baseline, participants who later transitioned into heavy drinking showed smaller left cingulate, pars triangularis, and rostral anterior cingulate volume, and less right cerebellar white matter volumes (p < .05), compared to continuous non-using teens. Over time, participants who initiated heavy drinking showed significantly greater volume reduction in the left ventral diencephalon, left inferior and middle temporal gyrus, and left caudate and brain stem, compared to substance-naïve youth (p < .05).ConclusionFindings suggest pre-existing volume differences in frontal brain regions in future drinkers and greater brain volume reduction in subcortical and temporal regions after alcohol use was initiated. This is consistent with literature showing pre-existing cognitive deficits on tasks recruited by frontal regions, as well as post-drinking consequences on brain regions involved in language and spatial tasks.