Association study of DRD2 and MAOA genes with subtyped alcoholism comorbid with bipolar disorder in Han Chinese

► The MAOA-uVNTR 3-repeat had a significant protective effect on the BP+ALC group. ► Interaction between MAOA-uVNTR 3-repeat and DRD2 A1/A2 is a risk factor for BP+ALC. ► The impact of the association between MAOA-uVNTR 3-repeat and DRD2 A1/A2 in BP+ALC.