Quick GuideSchizophrenia: Symptoms, Types, Causes, Treatment

To diagnose schizoaffective disorder, one first has to rule out any medical condition that may be the actual cause or contributing factor for the mood and behavioral changes. Once medical causes have been looked for and not found, a mental illness such as schizoaffective disorder could be considered. The diagnosis will best be made by a licensed mental health professional, like a psychiatrist, clinical psychologist, psychiatric nurse, nurse practitioner, or physician's assistant, who can evaluate the patient and carefully sort through a variety of mental illnesses that might look similarly upon the initial examination. Such illnesses include any other thought disorder, like schizophrenia spectrum disorders, including schizophrenia, delusional disorder, and schizotypal personality disorder, as well as any disorder in which both mood symptoms and psychosis may occur or appear to occur, like borderline personality disorder, dissociative identity disorder, bipolar disorder with psychotic features, or major depression with psychotic features.

The mental health professional will examine someone in whom schizoaffective disorder is suspected either in an office or in the emergency department. The practitioner's role is to ensure that the patient doesn't have any medical problems, including active drug use or exposure to environmental toxins, since symptoms of those conditions can mimic the thought disorder and mood swings of schizoaffective disorder. The health care professional takes the patient's history and performs a physical examination. Laboratory and other tests, sometimes including a computerized tomography (CT) scan of the brain, are performed. Physical findings can relate to the symptoms associated with schizoaffective disorder or the medications the person may be taking.