Differential Diagnosis and Therapeutic Management of Schizoaffective Disorder
An estimated 1 of 4 inpatient psychiatry admissions is attributed to schizoaffective disorder (SAD). (1), (2) Lifetime prevalence of this important yet poorly understood disorder ranges between 0.5% and 0.8%. Despite its common presentation, few studies with selectively enriched SAD patient populations have been conducted; therefore, information about the phenomenology and treatment of SAD derives more from observational studies or small, post hoc analyses, than from large-scale randomized studies.
SAD is a heterogeneous clinical construct marked by mixed psychotic and affective symptoms, the inter-relationships of which vary considerably between and within individuals, presenting formidable challenges even to experienced psychiatrists. (3), (4) The bipolar and depressive subtypes of SAD exert different influences on perception, cognition, affect, mood, and physiological functioning. Knowledge about the clinical features, differential diagnosis, clinical course, and management of SAD has been shaped by diversity of opinion more than by consensus within the field, precluding even the most rudimentary definitions for standard of care. In the American nosology, diagnostic inclusion and exclusion criteria were not specified prior to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV). International Classification of Diseases and Related Health Problems 10th revision (ICD-10) criteria for SAD differ in several fundamental respects from those of DSM-IV (Table 1, page S4) (3), (5) and likely contribute to variations in diagnostic practice in the United States and abroad. The paucity of established treatments for SAD, particularly with agents approved by the U.S. Food and Drug Administration, may further diminish the ability of clinicians to diagnose and treat SAD with confidence.
TABLE 1 DSM-IV TR and ICD-10 diagnostic criteria for SAD Diagnostic Criteria Affective Schizophrenic Duration DSM-IV Major depressive, Meeting Criterion A Major depressive manic, or mixed for schizophrenia episode 2 weeks; episode (presence of mixed or manic 1 [greater than or week Psychotic equal to]2 symptoms 1 month to delusions, meet Criterion A for hallucinations, schizophrenia disorganized speech, behavioral disturbances, or negative symptoms) ICD-10 Prominent manic, One, preferably 2 of Mania [greater than depressive, or (a)-(d) symptoms for or equal to] 1 week; mixed symptoms schizophrenia * depression [greater than or equal to]2 weeks Diagnostic Criteria Simultaneity Additional DSM-IV During the same period of the Delusions or hallucinations illness for [greater than or equal to] 2 weeks without prominent mood symptoms Mood symptoms as a substantial portion of the total illness duration ICD-10 Simultaneous, or at least within a few days of each other * Symptoms include (a) thought echo, thought insertion or withdrawal, or thought broadcasting; (b) delusions of control, influence or passivity, clearly referred to body or limb movements or specific thoughts, actions, or sensations; delusional perception; (c) hallucinatory voices giving a running commentary on the patient's behavior, or discussing him between themselves, or other types of hallucinatory voices coming from some part of the body; (d) persistent delusions of other kinds that are culturally inappropriate and completely impossible (eg, being able to control the weather, being in communication with aliens from another world). …