Stability of schizoaffective disorder in correlation with duration of follow-up: Retrospective analysis

Background/Aims: Previous studies have indicated that the validity and reliability of schizoaffective disorder (SAD) diagnosis according to the DSM-IV criteria are insufficient, and that the stability of the diagnosis is poor. However, no study has examined exclusively the diagnostic stability of SAD. The aims of this study were to examine the longitudinal stability of the diagnosis of SAD and SAD subtypes among a large sample of patients, and to examine demographic and clinical variables as predictors of diagnostic stability. Methods: A retrospective chart review of 123 inpatients who were admitted to Geha Mental Health Center between the years 2000 and 2005, and who had been diagnosed with SAD at some stage of their illness. We compared the group of patients whose diagnosis of SAD had remained stable and the group of patients whose diagnosis had changed. Results: The diagnostic stability for SAD was 73.1%. Diagnostic transitions were mainly from and towards schizophrenia. We found an association between the SAD bipolar subtype and higher rates of diagnostic stability. The time that had elapsed since SAD diagnosis was made was significantly shorter in the group of patients with stable diagnosis than in the group of patients whose diagnosis had changed (p = 0.037). Conclusions: The diagnostic stability of SAD might be higher than previously reported. Patients who are diagnosed with SAD manic subtype have a higher tendency to retain their diagnosis than patients with other SAD subtypes. The diagnostic changes are derived from manifestations of new symptoms in the course of the disease. Clarification of the current diagnostic criteria in order to enable a more precise utilization of the SAD subtype diagnoses is warranted. Study Limitations: (a) The study design was retrospective and further prospective studies are needed to establish our findings; (b) there is a misusage of the SAD subtype definitions, thus conclusions regarding polarity of SAD and stability of diagnosis are limited, and (c) the population studied was comprised of inpatients, therefore generalization to the outpatient population should be done with caution.