Self-reports of depression and state-trait anxiety: evidence for differential assessment

Several researchers have found anxiety and depression to be indistinguishable in nonclinical samples and have suggested that both constructs may be components of a general psychological distress process. Another possibility is that overlap is due to the psychometric limitations of scales used. A series of exploratory factor analyses were conducted in a nonclinical sample (N = 605) using the Beck Depression Inventory (BDI; Beck, 1978), the State-Trait Anxiety Inventory (STAI; Spielberger, 1983), and the Endler Multidimensional Anxiety Scales (EMAS; Endler, Edwards, & Vitelli, 1991). Both state and trait anxiety and depression could be differentiated with the BDI and the EMAS but not with the STAI. Some theoretical models of negative affectivity or general psychopathology may be premature.