Beck Depression Inventory II: evaluation of the psychometric properties and cut-off points in a Turkish adult population

Abstract

Numerous studies have been previously conducted to assess the Beck Depression Inventory-II's [BDI II; Beck et al., 1996] psychometric properties. However, none of these studies has examined whether the original cut-off scores were applicable to other cultures. Thus, in addition to evaluating its psychometric properties, we also determined the cut-off scores of the BDI II for the Turkish population. Data from nonclinical (n = 362) and clinical psychiatric outpatients diagnosed as depressive disorder according to DSM-IV criteria (n = 176) were gathered. Analyses for internal consistency and test-retest reliabilities and for convergent and discriminant validities were computed. Two confirmatory factor analyses, one derived from the present exploratory factor analyses and the other proposed in the original study were conducted for both groups. A receiver operating characteristics curve was utilized to determine the cut-off scores for the Turkish population revealing 0-12 for minimal, 13-18 for mild, 19-28 for moderate and 29-63 for severe depression. The internal consistency for the nonclinical and clinical groups were .90 and .89, respectively; test-retest stability was also high (r = .94). Convergent and discriminant validity results were satisfactory. Findings confirmed the present model for the clinical group and equally confirmed both models for the nonclinical group. Furthermore, the cut-off scores to classify minimal, mild, moderate, and severe depression were quite akin to the cut-off points previously suggested for the American population. Taken as a whole our findings revealed that BDI II has sound psychometric properties and comparable cut-off scores for the Turkish population.