title: The validity and reliability of the German version of the Somatoform Dissociation Questionnaire (SDQ-20).
abstract: The present study investigated the validity of the German version of the Somatoform Dissociation Questionnaire (SDQ-20), a scale designed to measure somatoform dissociative symptoms. Somatoform dissociation involves physical manifestations of a dissociation of the personality and is considered a unique entity in the phenomenological spectrum of dissociation. The validity and reliability of the German version of the SDQ-20 was examined using a sample of 225 patients with (n = 39) and without dissociative disorders who were recruited from several in- and outpatient psychiatric clinics. Patients were assessed using structured diagnostic interviews; diagnostic checklists; and self-rating scales for dissociation, and posttraumatic stress. Patients with dissociative disorders reported significantly more (p < .001) somatoform dissociative symptoms than patients without dissociative disorders (criterion validity). Significant correlations (p < .001) were found between scores of somatoform dissociation, psychoform dissociation, posttraumatic stress symptoms, and traumatic childhood experiences (construct validity). Reliability was corroborated by a Cronbach's alpha coefficient of .91 and a test-retest correlation of .89. A component factor analysis suggested unidimensionality of the SDQ-20. In conclusion, the psychometric properties and cross-cultural validity of the German version of the SDQ-20 are excellent. Our results form the basis for the further study of somatoform dissociation in German-speaking populations.
authors.affiliation: Clinic for Psychiatry and Psychotherapy, University Hospital, Zurich, Switzerland. christoph.mueller-pfeiffer@access.uzh.ch
authors.forename: Christoph
authors.initials: C
authors.lastname: Mueller-Pfeiffer
authors.forename: Sonja
authors.initials: S
authors.lastname: Schumacher
authors.forename: Chantal
authors.initials: C
authors.lastname: Martin-Soelch
authors.forename: Aju P
authors.initials: AP
authors.lastname: Pazhenkottil
authors.forename: Gustav
authors.initials: G
authors.lastname: Wirtz
authors.forename: Christoph
authors.initials: C
authors.lastname: Fuhrhans
authors.forename: Esther
authors.initials: E
authors.lastname: Hindermann
authors.forename: Herbert
authors.initials: H
authors.lastname: Assaloni
authors.forename: David P
authors.initials: DP
authors.lastname: Briner
authors.forename: Michael
authors.initials: M
authors.lastname: Rufer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002649:Child Abuse / Q000523:psychology; D015897:Comorbidity; D003431:Cross-Cultural Comparison; D004213:Dissociative Disorders / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D005858:Germany; D006801:Humans; D008016:Life Change Events; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000523:psychology; D008875:Middle Aged; D010555:Personality Inventory / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D013001:Somatoform Disorders / Q000175:diagnosis* / Q000523:psychology; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis / Q000523:psychology; D011795:Surveys and Questionnaires; D013557:Switzerland; D014175:Translating; D055815:Young Adult