TESTING A TRIPARTITE MODEL .1. EVALUATING THE CONVERGENT AND DISCRIMINANT VALIDITY OF ANXIETY AND DEPRESSION SYMPTOM SCALES

L. A. Clark and D. Watson (1991) proposed a tripartite model that grou ps symptoms of depression and anxiety into 3 subtypes: symptoms of gen eral distress that are largely nonspecific, manifestations of somatic tension and arousal that are relatively unique to anxiety, and symptom s of anhedonia and low Positive Affect that are specific to depression . This model was tested in 5 samples (3 student, 1 adult, and 1 patien t sample) using the Mood and Anxiety Symptom Questionnaire (MASQ; D. W atson & L. A. Clark, 1991), which was designed to assess the hypothesi zed symptom groups, together with other symptom and cognition measures . Consistent with the tripartite model, the MASQ Anxious Arousal and A nhedonic Depression scales both differentiated anxiety and depression well and also showed excellent convergent validity. Thus, differentiat ion of these constructs can be improved by focusing on symptoms that a re relatively unique to each.