Schizoaffective disorder is among the most frequently misdiagnosed psychiatric disorders in clinical practice. Due to concerns about the reliability and utility of the diagnostic criteria for schizoaffective disorder, some researchers have proposed revisions, while others have suggested altogether removing the diagnosis from the Diagnostic and Statistical Manual of Mental Disorders. The term schizoaffective disorder first appeared as a subtype of schizophrenia in the first edition of the DSM. It eventually became its own diagnosis despite a lack of evidence for unique differences in etiology or pathophysiology. Therefore, there have been no conclusive studies on the etiology of the disorder.
The specific DSM-5 criteria for schizoaffective disorder are as follows:
An uninterrupted duration of illness during which there is a major mood episode (manic or depressive) in addition to criterion A for schizophrenia; the major depressive episode must include depressed mood (A).
Criterion A for schizophrenia is as follows:
Two or more of the following presentations, each present for a significant amount of time during a 1-month period (or less if successfully treated). At least one of these must be from the first three below.
- Delusions
- Hallucinations
- Disorganized speech (e.g., frequent derailment or incoherence).
- Grossly disorganized or catatonic behavior
- Negative symptoms (i.e., diminished emotional expression or avolition.)
Hallucinations and delusions for two or more weeks in the absence of a major mood episode (manic or depressive) during the entire lifetime duration of the illness (B).
Symptoms that meet the criteria for a major mood episode are present for most of the total duration of both the active and residual portions of the illness (C).
The disturbance is not the result of the effects of a substance (e.g., a drug of misuse or a medication) or another underlying medical condition (D).
The following are specifiers based on the primary mood episode as part of the presentation.
Bipolar type: includes episodes of mania and sometimes major depression.
Depressive type: includes only major depressive episodes.
Patient must meet the criteria for A-D above to be diagnosed with schizoaffective disorder. It is not enough to symptoms of schizophrenia while meeting the criteria for a major mood episode.
The next step of evaluation is the objective and physical portion. A thorough mental status examination (MSE), physical examination, and neurologic examination should be completed to help rule out other differential diagnoses.
Because of criteria that encompass both psychotic and mood symptoms, schizoaffective disorder is easy to mistake for other mental disorders. Disorders that must be ruled out during the workup of schizoaffective disorder include:
- Schizophrenia
- Major depressive disorder with psychotic features
- Bipolar disorder
Schizophrenia and Schizoaffective Disorder: There has to be a definite period of at least two weeks in which there are only psychotic symptoms (delusions and hallucinations) without mood symptoms to diagnose schizoaffective disorder. However, a major mood episode (depression or mania) is present for the majority of the total duration of the illness. Once the psychotic symptoms predominate the majority of the total duration of the illness, the diagnosis leans towards schizophrenia. Also, schizophrenia requires 6 months of prodromal or residual symptoms; schizoaffective disorder does not require this criterion.
Major Depressive Disorder Psychotic Features and Schizoaffective Disorder: Patients with major depression with psychotic features (MDD with PF) only experience psychotic features during their mood episodes. In contrast, schizoaffective requires at least 2 weeks in which there are only psychotic symptoms (delusions and hallucinations) without mood symptoms. Patients with MDD with PF do not meet criterion A of schizoaffective disorder.
Bipolar Disorder and Schizoaffective Disorder: Similar to the contrasts of MDD w/ PF, patients with bipolar disorder with psychotic features only experience psychotic features (delusions and hallucinations) during a manic episode. Again, schizoaffective requires a period of at least 2 weeks in which there are only psychotic symptoms without mood symptoms. Psychotic features in bipolar disorder do not meet criterion A of schizoaffective disorder.
Wy TJP, Saadabadi A. Schizoaffective Disorder. [Updated 2023 Mar 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK541012/