Schizoaffective disorder is a psychiatric disorder characterized by features of both schizophrenia and a mood disorder. It can be further divided into schizoaffective bipolar type or schizoaffective depressive type, depending on the mood disorder symptoms. Schizoaffective bipolar type is characterized by episodes mania and depression (although a depressive component is not mandatory for a diagnosis of this subtype) as part of the mood disorder component whereas schizoaffective depressive type is characterized by solely depressive symptoms as part of the mood disorder component. It can be difficult to diagnose seeing how bipolar I disorder can involve schizophrenia-like symptoms (like hallucinations/delusions) during episodes of mania. Likewise schizophrenia itself often causes depressive symptoms, so it can be difficult to distinguish it from schizoaffective disorders. Likewise there is also a subtype of major depression called psychotic depression that has symptoms of both depression and psychosis (which are also seen in schizophrenics/those with schizoaffective disorder).