Hippocampus-Ventral Striatum Connectivity Is Associated With Binge Drinking Frequency in Adults.

Contextual information, such as spatial locations and social groups, are known to propagate reward-seeking behavior including binge drinking. Animal models suggest that context-evoked drug and alcohol seeking emerges from hippocampal projections to the ventral striatum (i.e., nucleus accumbens). While binge drinking has been associated with adverse structure and function of both the ventral striatum and hippocampus, the anatomical relevance of this circuit in humans has largely been inferred from volumetric studies investigating these regions separately. Using diffusion MRI tractography in adults ages 22-35 (N = 593), we examined hippocampal-ventral striatum (HPC-VS) connectivity in relation to binge drinking. We found that greater left hemisphere HPC-VS connectivity was associated with greater past-year binge drinking frequency (b = 0.17, p = 0.027). In the right-hemisphere, an HPC-VS × sex interaction emerged for binge drinking frequency (b = 0.17, p = 0.031), such that greater right-hemisphere connectivity was associated with greater binge drinking frequency in females but lower binge drinking frequency in males. These findings demonstrate hemisphere- and sex-specific associations between hippocampal-striatal pathways and alcohol use, implicating structural variability in this circuit as a correlate of vulnerability to alcohol consumption that may be problematic.