Here we confirm our prior work21 by demonstrating in a larger sample that the combination of relatively low threat-related amygdala and relatively high reward-related VS reactivity represent a neural risk phenotype for stress-related problem drinking in young adult university students. We also extend this prior work by further demonstrating that the opposite pattern of relatively high threat-related amygdala and relatively low reward-related VS reactivity also predicts stress-related problem drinking. In addition, we demonstrate that the relationship between stress and problem drinking is mediated by higher impulsivity in the form of steeper monetary delay discounting for those with high VS-low amygdala reactivity and by anxious/depressive symptomatology for those with the opposite neural risk phenotype. Across both neural phenotypes, we found that greater divergence or mismatch between VS and amygdala reactivity predicted greater risk for problem drinking. In contrast, balance between VS and amygdala reactivity (i.e., either both low or both high) was protective against stress-related problem drinking. Finally, for those individuals with the low VS-high amygdala risk phenotype we found that stress not only predicted the presence of a DSM-IV diagnosed AUD at the time of neuroimaging, but also the subsequent self-reported problem drinking three months in the future.
