Psychiatry has used the term “schizoaffective disorder” for more than 60 years, but its specific meaning remains uncertain. Patients who meet its diagnostic criteria typically present with a confusing blend of mood and psychotic symptoms, and we often classify them as being schizoaffective because we don’t know where else to put them.
Much of our difficulty in trying to determine what schizoaffective disorder is can be blamed on insufficient data. We do not know the specific cause of either schizophrenic or mood disorders, and today’s concepts of these broad diagnoses probably encompass multiple etiologies.
Based on the evidence and clinical experience, this article presents:
- the evolution of schizoaffective disorder as a psychiatric diagnosis
- the four main concepts that attempt to explain the disorder’s cause
- and a practical approach for managing these patients’ complicated symptoms.
Origins of schizoaffective disorder
When Jacob Kasanin1 riginated the term schizoaffective disorder in 1933, psychiatry was struggling to integrate Emil Kraepelin’s and Eugene Bleuler’s two competing and complementary schemes for understanding psychotic disorders.
Kraepelin had proposed that the major psychoses could be divided between dementia praecox and manic-depressive insanity (and to a lesser extent, paraphrenia), based on the presenting symptoms and—importantly—course of illness:2
- Manic-depressive insanity typically included periods of full recovery of mental functions between episodes.
- Dementia praecox was defined by a steady deterioration of mental function and personality from which patients rarely recovered.
DSM-IV CRITERIA FOR SCHIZOAFFECTIVE DISORDER
- An uninterrupted period of illness during which, at some time, there is either a major depressive episode, a manic episode, or a mixed episode concurrent with symptoms that meet Criterion A for schizophrenia:
- During the same period of illness, there have been delusions or hallucinations for at least 2 weeks in the absence of prominent mood symptoms.
- 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.
- 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.
Specific type:
Bipolar type: If the disturbance includes a manic or a mixed episode (or a manic or a mixed episode and major depressive episodes)
Depressive type: If the disturbance only includes major depressive episodes.
Source: Diagnostic and statistical manual of mental disorders (4th ed., TR). Washington, DC: American Psychiatric Association, 2000.
This distinction was a landmark in psychiatry but did not offer a specific understanding of the mental or brain dysfunctions underlying these conditions nor a cross-sectional means to diagnose a patient’s condition.
Bleuler was less concerned with predicting course and outcome. Instead, he wished to understand his observations that patients commonly exhibited a disjunction among psychological processes that were integrated in healthy individuals.3 He described the cause of this loss of psychological integration as the “schizophrenias” or, literally, “split mind.” In the schizophrenias, he identified symptoms that seemed to reflect this psychological disjunction, such as flat affect, ambivalence, and splitting of cognition from emotion and behavior.
Because Kraepelin described many of these same symptoms in dementia praecox, clinicians tended to equate the schizophrenias with dementia praecox. However, many more patients with Bleuler’s schizophrenia recovered than did those with Kraepelin’s dementia praecox (essentially by definition). Therefore, some “schizophrenic” patients appeared to meet Kraepelin’s diagnosis of manic-depressive insanity. At this point, Kasanin stepped into the fray with his concept of schizoaffective disorder.
Kasanin’s conceptualization
Kasanin recognized that many patients exhibited a blending of Bleuler’s schizophrenia symptoms with those of Kraepelin’s manic-depressive (affective) illness.1 Moreover, unlike patients with dementia praecox, these blended patients exhibited:
- good premorbid adjustment
- typically a sudden illness onset with marked emotional turmoil
- few symptoms of withdrawal or passivity
- and a relatively short course with complete recovery.
In reporting these patients and subsequently originating the term “schizoaffective psychosis,” Kasanin tried to identify a homogeneous patient population that could be distinguished from the more broadly conceptualized Bleulerian schizophrenias and the more narrowly defined Kraepelinian categories.
The term “schizoaffective disorder” has evolved from this beginning. Interestingly, most—if not all—of the nine cases reported by Kasanin would be diagnosed with an affective disorder with psychotic features under today’s diagnostic criteria.4 Nonetheless, the term “schizoaffective disorder” was adopted by psychiatry (particularly in the United States) and has been used to classify patients who present with features of both schizophrenia and affective illness but cannot be clearly described as having either.
Evolutions from DSM-I to DSM-III
In American nosology, schizoaffective disorder was included as a subtype of schizophrenia in DSM-I (1952)5 and DSM-II (1968)6 and then reclassified in DSM-III (1980)7 as a “psychotic disorder not elsewhere classified.” Remarkably, none of these classifications provided criteria for diagnosing schizoaffective disorder.