Hippocampal volumes in adolescents with and without a family history of alcoholism.

Objective: The hippocampus may be vulnerable to the effects of heavy alcohol use during adolescence, which is a time of continued neurodevelopment. However, differences in hippocampal volume may be due to risk factors such as a family history (FH) of alcoholism. We examined hippocampal volumes in youth with and without a FH of alcoholism prior to the initiation of alcohol use.

Methods: Participants were demographically matched adolescents (aged 12-14) with positive (n = 15; FHP) and negative (n = 15; FHN) FH of alcoholism. Each group consisted of 10 males and 5 females with minimal previous substance use. Manual hippocampal tracings were completed on high-resolution magnetic resonance images by reliable raters, and intracranial volumes were controlled in analyses.

Results: FH groups did not differ on memory or hippocampal volumes, but group x gender interactions (p < .05) indicated that FHP males had larger left hippocampi than FHN males. Females showed greater left versus right hippocampal asymmetry, while males showed larger right versus left asymmetry. For all adolescents, larger right hippocampal volumes predicted poorer delayed visual memory (p < .01).

Conclusions: Alcoholism risk factors, such as family history of alcoholism, may differentially influence adolescent hippocampal development for boys as compared to girls. Results suggest that FH does not account for prior findings of reduced left hippocampal volumes in heavy drinking youth. Findings are preliminary, but suggest that future studies examining the effects of alcohol use on the adolescent brain should consider the influence of FH, especially among boys.