Spanish experimental version of the State-Trait Depression Questionnaire (ST-DEP: Trait sub-scale (T-DEP)

This study presents the first validity and reliability data for the trait subscale, T-Dep, of the Spanish Experimental Version of the State and Trait Depression Questionnaire, ST-Dep: Euthymia and Dysthymia (Ritterband and Spielberger, 1996; Spielberger, 1999). The data were obtained from a sample of 264 university students. The internal consistency values for the T-Dep were high (.95). The convergent validity indexes for the Beck Depression Inventory (Beck, Rush, Shaw, and Emery, 1979), the Zung Self-Rating Depression Scale (Zung, 1965), and the Peñate Basic Depression Questionnaire (Peñate, 2001) were also high, with indexes ranging from .68 to .82. The correlation between State-Trait Anxiety Inventory (Spielberger, Gorsuch, and Luschene, 1970) and all scales used in this study, was high, once again indicating the usual overlapping between anxiety and depression seen in most depression inventories. The test-retest values from a three and one half month time interval (one hundred twelve days) are elevated (.71). Similarly, there appear to be significant gender differences for all the administered scales, with women obtaining the highest scores. A factorial analysis of the main axis revealed a principal factor for all of the constructed items in this experimental version of the T-Dep. The last, promax rotation showed two clear main factors similar in size: negative affectivity (Dysthymia) and positive affectivity (Euthymia).