We found several significant differences between the genetic correlations with AUDIT-P and AUDIT-C. These differences were particularly pronounced for psychiatric and behavioral traits. AUDIT-P was positively genetically correlated with psychopathology (schizophrenia, bipolar disorder, MDD, ADHD), personality traits including neuroticism, and regional brain volumes. These associations have previously been observed at the phenotypic level; AUDs commonly co-occur in individuals with schizophrenia (38), bipolar disorder (39), MDD (40) and adult ADHD (41). Intriguingly, genetic risk for high AUDIT-C score was negatively correlated with MDD and ADHD demonstrating that a distinct genetic component of AUDIT-P is shared with genetic risk for psychiatric disease. Regional volume abnormalities in subcortical brain regions of AUD individuals have been reported (42–44), however, it is unclear whether these alterations are a result of high alcohol drinking or a pre-existing susceptibility. We identified a positive genetic correlation between AUDIT-P and increased caudate volume; however, the majority of studies report reductions in regional brain volumes associated with AUD.
