The comorbidity structure of fear, distress and compulsive disorders in an acute psychiatric sample

Body dysmorphic disorder (BDD) and obsessive-compulsive disorder (OCD), collectively referred to as compulsive disorders, have typically not been included in structural research on the internalizing spectrum due to low prevalence in community samples. The current study examined the higher-order structure of anxiety, depressive and compulsive disorders among patients in a psychiatric partial hospital program (N = 2,178). We applied confirmatory factor analysis to diagnostic data obtained at admission and compared several competing models of the comorbidity structure. A one-factor model accounted well for the co-occurrence of all the disorders. A two-factor model comprised of fear and distress factors, wherein compulsive disorders loaded on fear, also fit the data well. However, a very large factor correlation (r = 0.86) suggested limited discriminant validity of fear and distress in the sample. Alternate models that featured a distinct compulsivity factor were not viable owing to large correlations between fear and compulsive disorders. Overall, our findings indicate that a broad internalizing dimensions underlies not only anxiety and depression, but also compulsive disorders, in an acute psychiatric population. Future studies using symptom-level data are needed to replicate these results and determine the structure of internalizing disorders from the bottom up, starting with narrowly defined symptom components.