Body and Social Anhedonia of Depression: A Bifactor Model Analysis.

The purpose of this study was to develop a statistical model of anhedonia of depression. The study included 748 healthy controls (350 women, 46.79%, age 21.27 ± 4.72) and 80 patients (32 women, 40%, age 38.36 ± 16.42). The Physical Anhedonia Scale (PhAS), the Social Anhedonia Scale (CSAS), the Positive and Negative Affect Scale (PANAS) and the Beck Depression Inventory(BDI) were administered. Classical Measurement Theory (CTT) and Item Response Theory (IRT) were applied to the collected data. We observed that the general factor of depression status was significantly related with positive emotion (r = -0.37, P < 0.05), negative emotion (r = 0.62, P < 0.05) and BDI (r = 0.48, P < 0.01). A significant difference also was observed between controls and patients. The bifactor model of anhedonia of depression provided a better fit to the data than a unidimensional model. The bifactor model appears to be useful to describe anhedonia in depression.