Abstract
The Epidemiology and Descriptive and Predictive Validity of DSM-IV Delusional Disorder and Subtypes of Schizophrenia
Author(s): Jaana Suvisaari , Jonna Perälä , Samuli I. Saarni , Hannu Juvonen , Annamari Tuulio-Henriksson, Jouko Lönnqvist 1Objective: We studied the clinical and epidemiological features of DSM-IV delusional disorder and schizophrenia subtypes in a general population-based sample and investigated the descriptive and predictive validity of these diagnoses. Method: The study was based on a nationally representative survey of 8,028 persons aged thirty years or over from Finland. DSM-IV psychotic disorders were diagnosed using the SCID-I interview and/or case note data. Lifetime severity of symptoms and course and outcome of the disorder were assessed using the Major Symptoms of Schizophrenia Scale. Based on information from the interview, case notes, and health care registers, we assessed current and lifetime treatment contacts, hospitalizations, and antipsychotic medication use. Results: The prevalences were 0.18% (95% CI 0.11–0.30) for delusional disorder; 0.24% (95% CI 0.15–0.37) for paranoid, 0.42% (95% CI 0.30–0.59) for undifferentiated and 0.16% (95% CI 0.09–0.27) for disorganized schizophrenia. Both delusional disorder and disorganized schizophrenia were distinct from the other groups. Delusional disorder was characterized by late age at onset, absence of symptoms other than delusions, and relatively good outcome. Only 50% of persons with delusional disorder had received inpatient treatment. Disorganized schizophrenia was associated with early onset, male preponderance, chronic course with long hospitalizations, and poor outcome. Paranoid and undifferentiated schizophrenia did not differ in terms of age at onset, course and outcome. Conclusions: The clinical utility of DSM-IV criteria for delusional disorder and disorganized schizophrenia is good. There are relatively few clinically significant differences between DSM-IV paranoid and undifferentiated schizophrenia