Factor structure of BDI in general population: The simplified Beck Depression Inventory and the theory of homeostatically protected mood

Objective. This study aimed to analyze the factor structure of the simplified Beck Depression Inventory BDI-S translated from German and attempted for a theoretical justification of its items based on the theory of homeostatically protected mood. BDI-S uses a frequency scale instead of the original rating of the degree of the measured behavior by separate descriptions (21x4 descriptions); thus creating a tool with a four times lower number of items. Method. The questions were answered by N = = 1108 people aged from 18 to 70. As in the case of BDI-II, the PAF (principal axis factoring) method and oblique rotation (Promax) were used on half of the participants to analyze the structure of BDI-S; and CFA was used on the other half of the participants. Gender invariance was verified and factor reliability was determined. Results. Using EFA the two-factor structure found by the authors of the original BDI-II questionnaire in students (cognitive-affective dimension, factor 1; and somatic dimension, factor 2) was not supported, but the somatic-affective and cognitive dimensions, which were found by the authors of the original BDI-II in patients (Beck et al., 1996) were supported. CFA confirmed the identified two-factor structure, which was invariant in terms of gender. Conclusions. The two identified dimensions of BDI-S in the general population represent the contents identified by BDI-II in patients. An attempt to apply the theory of homeostatically protected mood seems to be unsuccessful for two reasons: a) In the questionnaire, depressed mood and loss of pleasure and interest are not sufficiently represented, namely, they were not represented by the separate factor in the results; b) In the general population, it can be expected that there will be no longer-lasting negative change in the homeostatically protected mood. Study limitation. The results may have been affected by online data collection at the time of the pandemic.