title: Prevalence of dissociative disorders in psychiatric in-patients: the impact of study characteristics.
abstract: OBJECTIVE
  Prevalence rates for dissociative disorders among psychiatric in-patients vary widely. The aim of this meta-analysis is to offer an explanation for these differences.
  
  
  METHODS
  Prevalence studies using a clinical diagnostic interview among psychiatric in-patients were included. Hypotheses concerning the impact of blind versus not blind designs, choice of diagnostic instrument and continental background were tested.
  
  
  RESULTS
  Nine studies met the inclusion criteria. In blind studies the prevalence rate for dissociative disorders was significantly lower (but not for DID). Studies using the SCID-D (compared to the DDIS) and European studies had significantly lower prevalence rates for both dissociative disorders as well as for DID.
  
  
  CONCLUSIONS
  The choice of diagnostic instrument and cultural differences in interpretation of symptoms are major explanations for differences in prevalence of dissociative disorders and DID. Comparative, blind research using both DDIS and SCID-D in the assessment of dissociative disorders is advised.
authors.affiliation: Psychiatric Hospital Willibrord, Heiloo, The Netherlands.
authors.forename: M C
authors.initials: MC
authors.lastname: Friedl
authors.forename: N
authors.initials: N
authors.lastname: Draijer
authors.forename: P
authors.initials: P
authors.lastname: de Jonge
mesh_terms: D003466:Cultural Characteristics; D004213:Dissociative Disorders / Q000453:epidemiology*; D006801:Humans; D007297:Inpatients; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D012720:Severity of Illness Index