In 2019, the Bipolar disorder Working Group of the Psychiatric Genomics Consortium (PGC) reported a multi-stage bipolar disorder genome-wide association study (PGC2 GWAS) of up to 20,352 cases and 31,358 controls of European descent. In this study, 30 loci were genome-wide significant, including 20 newly identified loci (Stahl EA, et al. Genome-wide association study identifies 30 loci associated with bipolar disorder. Nature Genetics, 51(5):793-803. [PMID:31043756]).