Here's what I read from the Illinois Tri County National Alliance for the Mentally Ill newsletter in early October 2011 concerning schizophrenia and schizoaffective:

quote "Schizophrenia also affects mood. While many individuals affected with schizophrenia become depressed, some also have apparent mood swings and even bipolar-like states. When mood instability is a major feature of the illness, it is called schizoaffective disorder meaning that elements of schizophrenia and mood disorders are prominently displayed by the same individual. It is not clear whether schizoaffective disorder is a distinct condition or simply a subtype of schizophrenia." end quote