 [ Symptoms ] what is the difference between bi polar and schizophrenia [ Disease ] schizophrenia is a psychotic disorder and bipolar disorder is a mood disorder but can also involve psychosis schizophrenia is less common than bipolar disorder and is usually first diagnosed in a person is late teens to late 20 is bipolar disorder is a fairly common mental disorder compared to schizophrenia bipolar disorder affects both men and women equally and can be initially diagnosed throughout a person is life