Genome-wide association study identifies 30 Loci Associated with Bipolar Disorder

ABSTRACT Bipolar disorder is a highly heritable psychiatric disorder that features episodes of mania and depression. We performed the largest genome-wide association study to date, including 20,352 cases and 31,358 controls of European descent, with follow-up analysis of 822 sentinel variants at loci with P<1×10 -4 in an independent sample of 9,412 cases and 137,760 controls. In the combined analysis, 30 loci reached genome-wide significant evidence for association, of which 20 were novel. These significant loci contain genes encoding ion channels and neurotransmitter transporters ( CACNA1C , GRIN2A , SCN2A , SLC4A1 ), synaptic components ( RIMS1 , ANK3 ), immune and energy metabolism components. Bipolar disorder type I (depressive and manic episodes; ~ 73% of our cases) is strongly genetically correlated with schizophrenia whereas bipolar disorder type II (depressive and hypomanic episodes; ~ 17% of our cases) is more strongly correlated with major depressive disorder. These findings address key clinical questions and provide potential new biological mechanisms for bipolar disorder.