Lifetime Alcohol Use Influences the Association between Future-Oriented Thought and White Matter Microstructure in Adolescents

Aims: Future orientation, or the ability to plan ahead and anticipate consequences, is a capacity that develops during adolescence, yet its underlying neurobiology is unknown. Previous independent reports suggest that reduced future orientation and altered white matter microstructure are associated with greater alcohol use in adolescents; however, these effects have not been studied in conjunction. This study investigated the association between future orientation and white matter microstructure as a function of lifetime alcohol use. Methods: Seventy-seven adolescents (46 female; 15-21 years of age) underwent diffusion weighted imaging (DWI) and completed a fifteen-item Future Orientation Questionnaire. Regression analyses assessed the association between self-reported lifetime alcohol use and future orientation, and the association between future orientation and white matter microstructure, as a function of lifetime alcohol use. Results: Adolescents with more lifetime alcohol use demonstrated lower future orientation. Voxel-wise DWI analyses revealed two regions, bilateral posterior corona radiata (PCR), where greater future orientation was associated with lower mean diffusivity in those with little or no history of alcohol use; however, this association was diminished with increasing rates of lifetime alcohol use. Conclusions: These findings replicate reports of reduced future orientation as a function of greater lifetime alcohol use and demonstrate an association between future orientation and white matter microstructure, in the PCR, a region containing afferent and efferent fibers connecting the cortex to the brain stem, which depends upon lifetime alcohol use. These findings provide novel information regarding the underlying neurobiology of future-oriented thought and how it relates to alcohol use.