The categorical diagnostic manuals do not reflect reality in their separation of psychosis (via the schizophrenia diagnosis) from mood disorder, nor do they currently emphasize the actual overlap found in real-life patients. Thus, they are likely to continue to introduce either-or conceptual and diagnostic error, by way of confirmation bias into clinicians mindsets, hindering accurate assessment and treatment.The new definition continues the lack of parsimony of the old definition. Simpler, clearer, and more usable definitions of the diagnosis were supported by certain members of the DSM-5 workgroup (see next paragraph); these were debated but deemed premature, because more "research [is] needed to establish a new classification system of equal or greater validity" to the existing system. Because of DSM-5s continuing problematic categorical foundation, schizoaffective disorders conceptual and diagnostic validity remains doubtful. After enough research is completed and data exists, future diagnostic advances will need to either eliminate and replace, or soften and bridge, the hard categorical separation of mood disorders from schizophrenia; most likely using a spectrum or dimensional approach to diagnosis.More parsimonious definitions than the current one were considered by Carpenter and the DSM-5 workgroup:
One option for the DSM-5 would have been to remove the schizoaffective disorder category and to add affective [or mood] symptoms [that is, mania, hypomania, mixed episode, or depression] as a dimension to schizophrenia and schizophreniform disorder or to define a single category for the co-occurrence of psychosis and mood symptoms.
Psychiatric rehabilitation, psychotherapy, and vocational rehabilitation are very important for recovery of higher psychosocial function. As a group, people with schizoaffective disorder that were diagnosed using DSM-IV and ICD-10 criteria (which have since been updated) have a better outcome, but have variable individual psychosocial functional outcomes compared to people with mood disorders, from worse to the same. Outcomes for people with DSM-5 diagnosed schizoaffective disorder depend on data from prospective cohort studies, which have not been completed yet. The DSM-5 diagnosis was updated because DSM-IV criteria resulted in overuse of the diagnosis; that is, DSM-IV criteria led to many patients being misdiagnosed with the disorder. DSM-IV prevalence estimates were less than one percent of the population, in the range of 0.5–0.8 percent; newer DSM-5 prevalence estimates are not yet available. Signs and symptoms
Schizoaffective disorder is defined by mood disorder-free psychosis in the context of a long-term psychotic and mood disorder. Psychosis must meet criterion A for schizophrenia which may include delusions, hallucinations, disorganized thinking and speech or behavior and negative symptoms. Both delusions and hallucinations are classic symptoms of psychosis. Delusions are false beliefs which are strongly held despite evidence to the contrary. Beliefs should not be considered delusional if they are in keeping with cultural beliefs. Delusional beliefs may or may not reflect mood symptoms (for example, someone experiencing depression may or may not experience delusions of guilt). Hallucinations are disturbances in perception involving any of the five senses, although auditory hallucinations (or "hearing voices") are the most common.