Abstract
ObjectiveThe diagnosis of schizoaffective disorder has long maintained an uncertain status in psychiatric nosology. Studies comparing clinical and biological features of patients with schizoaffective disorder to patients with related disorders [e.g., schizophrenia and bipolar disorder] can provide an evidence base for judging the validity of the diagnostic category. However, because most prior studies of schizoaffective disorder have only evaluated differences between groups at a static timepoint, it is unclear how these disorders may be related when the entire illness course is taken into consideration.MethodsWe ascertained a large cohort [N = 993] of psychiatric patients with a range of psychotic diagnoses including schizophrenia with no history of major affective episodes [SZ−; N = 371], schizophrenia with a superimposed mood syndrome [SZ+; N = 224], schizoaffective disorder [SAD; N = 129] and bipolar I disorder with psychotic features [BPD+; N = 269]. Using cross-sectional data we designed key clinical and neurocognitive dependent measures that allowed us to test longitudinal hypotheses about the differences between these diagnostic entities.ResultsLarge differences between diagnostic groups on several demographic and clinical variables were observed. Most notably, groups differed on a putative measure of cognitive decline. Specifically, the SAD group demonstrated significantly greater post-onset cognitive decline compared to the BP+ group, with the SZ− and SZ+ group both exhibiting levels of decline intermediate to BPD+ and SAD.ConclusionsThese results suggest that schizoaffective disorder may possess distinct features. Contrary to earlier formulations, schizoaffective disorder may be a more severe form of illness.
Highlights
Since its initial description by Kasanin [1] the diagnosis of schizoaffective disorder [SAD] has been at the center of controversy regarding the relation between psychotic and affective disorders
According to current diagnostic criteria (DSM-IVTR) [5], a patient with symptoms meeting the diagnostic criteria for both SZ and a manic episode may receive a diagnosis of either SZ with bipolar disorder NOS (BPD NOS), SAD or bipolar disorder (BPD) with psychotic features
The total sample was divided based on DSM-IV diagnoses and included 1] schizophrenia with no history of major affective episodes (SZ2; N = 371), 2) schizophrenia with a superimposed mood syndrome (SZ+; N = 224), 3) schizoaffective disorder (SAD; N = 129) and 4) bipolar I disorder with psychotic features (BPD+; N = 269)
Summary
Since its initial description by Kasanin [1] the diagnosis of schizoaffective disorder [SAD] has been at the center of controversy regarding the relation between psychotic and affective disorders. Described as a disorder in which patients presented with concomitant and severe affective and psychotic symptoms, SAD was conceptualized as a ‘‘good outcome’’ sub-type of schizophrenia (SZ) [2,3] It was not until the publication of the 3rd edition of the Diagnostic and Statistical Manual (DSM-III) of the American Psychiatric Association that SAD became a separate and more refined diagnostic entity and strict operational criteria for the diagnosis of SAD were not described until the publication of the DSM-IIIR [4]. If none of these criteria are met, a diagnosis of SAD is
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
