Hippocampal Volumes in Adolescents with and without a Family History of Alcoholism

Abstract

Background and Objectives: 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). Conclusion and Significance: 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.

Keywords :

• adolescence
• alcohol
• family history of alcoholism
• gender
• hippocampus
• memory

ACKNOWLEDGMENTS

This research was supported by grants R01 AA13419 (Tapert), 5 T32 AA013525 (Hanson; PI: Edward Riley), K08 NS52147 (Nagel), and F32 DA020206 (Medina) from the National Institutes of Health. Portions of this study were presented at the 2nd International Conference on Applications of Neuroimaging to Alcoholism in 2008. The authors would like to thank Veronique Boucquey, Sonja Eberson, Jesse Feng, Alejandra Infante, Sonia Lentz, Andria Norman, and Lindsay Squeglia for their contributions to this project.

Declaration of Interests

The authors have no conflicts of interest to disclose. The authors alone are responsible for the content and writing of the paper.