Reliability and validity of the Beck Depression Inventory-Fast Screen for medical patients in the general German population.

BACKGROUND: The Beck Depression Inventory Fast Screen (BDI-FS) is a self-report instrument for the detection of depression in youths and adults. It measures the severity of the depression, corresponding to the non-somatic criteria for the diagnosis of a major depression according to DSM-5. Until now the psychometric properties of the instrument have not been studied in the general population.

METHODS: In 2012, a survey representative for the Federal Republic of Germany was conducted. In addition to the BDI-FS, further self-rating questionnaires as well as a demographic questionnaire were administered.

RESULTS: Altogether, 4480 people were surveyed with a return rate of 56.1% (N=2467 persons). Approximately 53% of those surveyed were women. The average age was 49.4 years (SD=18.0), with a range of 14-91 years. For the BDI-FS total-scores, a coefficient α of .84 was determined (women: α=.83; men: α=.85). In addition, a convergent validity (r=.67) was determined with the Patient Health Questionnaire (PHQ-9). The discriminant validity of the BDI-FS can be classified as satisfactory. Based on a confirmatory factor analysis, the one-dimensionality of the BDI-FS could be confirmed, achieving very good fit indices (total sample: RMSEA=.058, CFI=.990, TLI=.986). An additional invariance analysis regarding gender, different age groups and their interaction resulted in strict invariance for the different multi-group analyses.

LIMITATIONS: Studies regarding stability have yet to be undertaken. A standard diagnostic interview for depression was not included.

CONCLUSION: The results support the reliability and validity of the BDI-FS for use with the general German population. Although in the present studies the BDI-FS was superior to the PHQ-9 in terms of its ability to discriminate between depressive and somatic symptoms, in future investigations the diagnostic efficiency of the BDI-FS should be compared with this and other depression inventories (e.g., PHQ-2, PHQ-8, and CES-D).