Bipolar II disorder (BDII) is one of the mental, neurological and substance-use disorders that constitute the global burden of disease. It is a neurodevelopmental psychiatric disorder, but little is known about its biological mechanism. Bipolar Disorder (BD) is highly heterogeneous contributing to challenges in identifying genetic contributions to risk of illness. Narrowing the clinical phenotype may help identify risk genes. This study was designed to identify genetic components of psychotic mania in bipolar disorder, and potential genetic overlap between bipolar disorder with psychosis and schizophrenia. Bipolar II disorder is a bipolar spectrum disorder characterized by at least one episode of hypomania and at least one episode of major depression. Diagnosis for bipolar II disorder requires that the individual must never have experienced a full manic episode, unless caused by an antidepressant. Otherwise, one manic episode meets the criteria for bipolar I disorder.