Alcohol consumption during adolescence is associated with reduced grey matter volumes.

BACKGROUND AND AIMS: Cognitive impairment has been associated with excessive alcohol use but its neural basis is poorly understood. Chronic excessive alcohol use in adolescence may lead to neuronal loss and volumetric changes in the brain. Our objective was to compare the grey matter volumes of heavy-drinking and light-drinking adolescents.

DESIGN: Longitudinal study: heavy-drinking adolescents without an alcohol use disorder and their light-drinking controls were followed up using questionnaires at three time points over ten years. Magnetic resonance imaging was conducted at the last time point.

SETTING: The area near Kuopio University Hospital, Finland.

PARTICIPANTS: The 62 participants were aged 22-28 years and included 35 alcohol users and 27 controls who had been followed up for approximately ten years.

MEASUREMENTS: Alcohol use was measured by AUDIT-C at three time points over 10 years. Participants were selected based on their AUDIT-C score. Magnetic resonance imaging was conducted at the last time point. Grey matter volume was determined and compared between heavy- and light-drinking groups using voxel-based morphometry on 3D T1-weighted MR images using predefined ROIs and a threshold of p < 0.05 with small volume correction applied on cluster level.

FINDINGS: Grey matter volumes were significantly smaller among heavy-drinking participants in the bilateral anterior cingulate cortex, right orbitofrontal and frontopolar cortex, right superior temporal gyrus and right insular cortex as compared to the control group (p < 0.05, FWE-corrected cluster level).

CONCLUSIONS: Excessive alcohol use during adolescence appears to be associated with an abnormal development of the brain grey matter. Moreover, the structural changes detected in the insula of alcohol users may reflect a reduced sensitivity to alcohol's negative subjective effects.