Hippocampal volume in adolescent-onset alcohol use disorders.

OBJECTIVE Alcohol use disorders (defined as DSM-IV alcohol dependence or abuse) are prevalent and serious problems among adolescents. As adolescence is marked by progressive hippocampal development, this brain region may be particularly susceptible to the adverse effects of adolescent alcohol use disorders. This study compared the hippocampal volumes of adolescents and young adults with adolescent-onset alcohol use disorders to those of healthy matched comparison subjects. METHOD Magnetic resonance imaging was used to measure the hippocampal volumes and volumes of comparison brain regions in 12 subjects with alcohol use disorders and 24 comparison subjects matched on age, sex, and handedness. RESULTS Both left and right hippocampal volumes were significantly smaller in subjects with alcohol use disorders than in comparison subjects. Total hippocampal volume correlated positively with the age at onset and negatively with the duration of the alcohol use disorder. Intracranial, cerebral, and cortical gray and white matter volumes and measures of the mid-sagittal area of the corpus callosum did not differ between groups. CONCLUSIONS In the mature brain, chronic alcohol use disorders are associated with graded global brain dysmorphology. Although the etiology, neuropsychological consequences, and permanence of these hippocampal findings need to be further examined, these findings suggest that, during adolescence, the hippocampus may be particularly susceptible to the adverse effects of alcohol.