Validation of a German Body Dysmorphic Disorder Screening Scale and Clinical Interview according to ICD-11 and DSM-5 in the General Population

Abstract

Background Body dysmorphic disorder (BDD) is an impairing psychological disorder with a high prevalence in clinical and cosmetic surgery settings. In the new ICD-11, BDD is grouped with the obsessive-compulsive spectrum disorders and the diagnostic criteria are updated, largely corresponding with the DSM-5. Available diagnostic interviews and screening scales for BDD are not based on these current criteria. In this paper, a newly developed screening questionnaire (BDD-S) and structured clinical interview (BDD-CI) according to the ICD-11 and DSM-5 criteria were preliminarily validated. Methods The BDD-S and the BDD-CI cover all core BDD symptoms. Open-ended questions allow for the addition of qualitative information on affected body parts and behavioural and mental aspects. We determined the internal consistency and construct validity of the BDD-S and suggested a cutoff value. We assessed a subsample with the BDD-CI and estimated a prevalence. The BDD-S was translated into Farsi and applied to an Iranian sample. BDD-S scores, social anxiety symptoms, and general psychopathological impairment were compared between a German and an Iranian sample. Results Internal consistency of the BDD-S was excellent (ω = .92). A high correlation with the body dysmorphic concerns and moderate correlations with measures of other mental disorders supported good construct validity. We determined a cutoff value of 19 for balanced sensitivity and specificity (sensitivity = 0.92, specificity = 0.87, AUC = .94). We estimated a prevalence of 2.76% for the German sample. The cultural comparison showed that the BDD-S score was higher in the Iranian sample. Conclusions With the BDD-S, we developed an economic and versatile screening instrument based on current diagnostic criteria, to be followed up with the BDD-CI when applicable, to obtain a clinical diagnosis. In the next step, the measures must be validated in larger clinical samples.