State depression: Mood or syndrome?

Abstract

A State Depression Scale was developed in order to register variations of depressive mood. The Scale has satisfactory reliability, as shown by its internal homogeneity and temporal stability. Concurrent validity of the Scale indicated that the Scale correlates with a POMS-D scale (r = 0.41; p < 0.00), and with the Depressive Personality Scale (r = 0.36; p < 0.00). Divergent validity of the Scale was tested by Scale's correlation with the two measures of state anxiety (STAI-S and POMS-A) and was shown to be unsatisfactory since it was as high as the Scale's correlation with scales of depressive affect. Principal Component Analysis extracted four factors: two broader factors, which included depressive-affective contents combined with anxious and depressive-cognitive symptoms, respectively; and another two factors which related to motivational and behavioral characteristics. Sensitivity of the Scale was tested in an experimental setting involving induction of depressive and euphoric mood. The Scale showed high ability to register changes following induction of depressive mood.