Aim: The aim of this work is to investigate differences between two non-schizophrenic, non-organic psychotic disorders, namely persistent delusional disorders (PDD) and acute and transient psychotic disorders (ATPD) according to ICD-10.
Method: In a prospective and longitudinal study, we compared all 43 inpatients with PDD who were treated at Halle-Wittenberg University Hospital during a 14-year period to a previously investigated cohort of 41 patients with ATPD in regard to demography, long-term symptomatic outcome, and social consequences. Sociobiographical data were collected using a semi-structured interview. Follow-up investigations were performed at a mean of 10–12 years after the onset of the disorder using standardized instruments.
Results: With the exception of the duration of the psychotic symptoms, the PDD patients were significantly different from the ATPD patients on various levels, such as sex ratio (female predominance only in ATPD), age at onset (older in PDD), the number of preceding stressful life-events in the index hospitalization (more frequent in ATPD), richness and variety of symptoms (higher in ATPD), and persistence of positive psychotic symptoms (in PDD). Patients with PDD had significantly less re-hospitalizations during the course of their illness. Long-term outcome was marked by chronicity of delusional symptoms and lower global functioning in PDD than in ATPD, while negative symptoms and loss of independence were infrequent in both conditions.
Conclusions: PDD differs from ATPD not only in the duration of the psychotic symptoms, but also in a variety of significant variables. They appear to be two separate entities within a psychotic spectrum.