Effects of alcohol use initiation on brain structure in typically developing adolescents.

BACKGROUND: Alcohol use in excessive quantities has deleterious effects on brain structure and behavior in adults and during periods of rapid neurodevelopment, such as prenatally. Whether similar outcomes characterize other developmental periods, such as adolescence, and in the context of less extensive use is unknown. Recent cross-sectional studies suggest that binge drinking as well as alcohol use disorders in adolescence are associated with disruptions in white matter microstructure and gray matter volumes.
OBJECTIVES: The current study followed typically developing adolescents from a baseline assessment, where no experience with alcohol was present, through two years, after which some individuals transitioned into regular use.
METHODS: Participants (n = 55) completed MRI scans and behavioral assessments.
RESULTS: Alcohol initiators (n = 30; mean baseline age 16.7 ± 1.3 years), compared to non-users (n = 25; mean baseline age 17.1 ± 1.2 years), showed altered patterns of neurodevelopment. They showed greater-than-expected decreases in cortical thickness in the right middle frontal gyrus from baseline to follow-up as well as blunted development of white matter in the right hemisphere precentral gyrus, lingual gyrus, middle temporal gyrus and anterior cingulate. Diffusion tensor imaging revealed a relative decrease over time in fractional anisotropy in the left caudate/thalamic region as well as in the right inferior frontal occipital fasciculus. Alcohol initiators did not differ from non-users at the baseline assessment; the groups were largely similar in other premorbid characteristics.
CONCLUSIONS: Subclinical alcohol use during mid-to-late adolescence is associated with deviations in neurodevelopment across several brain tissue classes. Implications for continued development and behavior are discussed.