DSM-IV-TR criteria
The following are the revised criteria for a diagnosis of schizoaffective disorder from the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR):
A. Two (or more) of the following symptoms are present for the majority of a one-month period:
* delusions
* hallucinations
* disorganized speech (e.g., frequent derailment or incoherence) which is a manifestation of formal thought disorder
* grossly disorganized behavior (e.g. dressing inappropriately, crying frequently) or catatonic behavior
* negative symptoms—affective flattening (lack or decline in emotional response), alogia (lack or decline in speech), or avolition (lack or decline in motivation)
If the delusions are judged to be bizarre, or hallucinations consist of hearing one voice participating in a running commentary of the patient's actions or of hearing two or more voices conversing with each other, only that symptom is required to meet criterion A above. The speech disorganization criterion is only met if it is severe enough to substantially impair communication.
AND at some time there is either a
* major depressive episode
* manic episode
* mixed episode
B. During the same period of illness, there have been delusions or hallucinations for at least two weeks in the absence of prominent mood symptoms.
C. Symptoms that meet criteria for a mood episode are present for a substantial portion of the total duration of the active and residual periods of the illness.
D. The disturbance is not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition.
[edit] Subtypes
Two subtypes of Schizoaffective Disorder exist and may be noted in a diagnosis based on the mood component of the disorder:
[edit] Bipolar type
if the disturbance includes
* a manic episode
* a mixed episode
Major depressive episodes usually, but not always, also occur in the bipolar subtype, however they are not required for DSM IV diagnosis.
[edit] Depressive type
The depressive type is noted when the disturbance includes major depressive episodes exclusively.
This subtype applies if major depressive episodes only (and no manic or mixed episodes) are part of the presentation.
[edit] Etiology and pathogenesis
Although the causes of schizoaffective disorder are unknown, it is suspected that this diagnosis represents a heterogeneous group of patients, some with aberrant forms of schizophrenia and some with very serious forms of mood disorders. There is little evidence that schizoaffective disorder is a distinct variety of psychotic illness. That is, the disorder appears exist on a continuum in-between schizophrenia and severe bipolar disorder and severe recurrent unipolar depression. Thus in a subgroup of patients with schizoaffective disorder, the illness appears to be comorbid (or co-ocurring) schizophrenia and mood disorder. It follows then that the etiology is probably more similar to that of schizophrenia in some cases and more similar to mood disorders in other cases.
Many different genes may be contributing to the genetic risk of acquiring this illness. In addition, many different biological and environmental factors are believed to interact with the person's genes in ways which can increase or decrease the person's risk for schizoaffective disorder. Schizophrenia spectrum disorders (of which schizoaffective disorder is a part) have been marginally linked to advanced paternal age at the time of conception, a common cause of mutations. [1]
