Psychological vulnerabilities in patients with major depression vs panic disorder.

The tripartite model (Clark & Watson, 1991: Clark, L. A., & Watson, D. (1991). Tripartite model of anxiety and depression: Psychometric evidence and taxonomic implications. Journal of Abnormal Psychology, 100, 316-336) posits that anxiety and depression share nonspecific features of neuroticism but that somatic arousal appears unique to anxiety, and low positive affect appears unique to depression. The present study controlled for these higher-order effects and evaluated the relative contributions of four, specific lower-order vulnerabilities (anxiety sensitivity, rumination, self-criticism, self-oriented perfectionism). Participants were 38 depressed patients and 38 patients with panic disorder matched as closely as possible for age and gender, and all were diagnosed using the same structured interview by an experienced clinician. Results from hierarchical logistic regression analysis were consistent with predictions from the tripartite model in that only the unique features of arousal and positive affectivity differentiated the two diagnostic groups. At a lower-order level, only anxiety sensitivity (and its facet of fear of physical symptoms) and a ruminative response style demonstrated incremental predictive ability. The discussion focuses on the relationships among these higher-order and lower-order variables, and their potential importance for understanding specific manifestations of psychopathology.