Four-dimensional structure underlying scales for depression anxiety and retardation: emergence of trapped anger and scale improvements.

Improvement of rating scales for anxiety and depression has insufficiently been based on their underlying multidimensional structure. The aim of this study was to detect the underlying symptom structure of 3 scales for anxiety, depression, and retardation from the Comprehensive Psychopathological Rating Scale (CPRS), to test its validity, and to investigate whether the scales developed from this structure have lower item overlap than the original scales. All items (N = 21) of the 3 subscales (Brief Anxiety Scale [BAS], Montgomery Asberg Depression Rating Scale [MADRS], and Motivational Inhibition) were selected. Principal components analysis was performed on the scores of 334 outpatients. Correlations between factor-regression scores on the CPRS components and scores on the Mood and Anxiety Symptom Questionnaire dimensions were analyzed. New rating scales based on the CPRS components were developed and compared with the original scales. Four CPRS components were found: depression, retardation, anxiety, and trapped anger. Each had a specific correlational pattern with the Mood and Anxiety Symptom Questionnaire dimensions. Overlap between the 4 new scales was lower than that between the original scales. A 4-dimensional symptom structure underlies CPRS scales for anxiety, depression, and retardation. This structure results in the detection of a scale for trapped anger and improvement of the 3 original scales.