Higher order compulsivity versus grooming dimensions as treatment targets for the DSM‐5 obsessive–compulsive and related disorders

Background Transdiagnostic definitions of obsessive–compulsive and related disorders (OCRDs) may represent useful treatment targets. The current study sought to characterize higher order dimensions underpinning the OCRDs in the Diagnostic and Statistical Manual of Mental Disorders—Fifth Edition, and examine their course during treatment. Methods Adult patients (N = 407) completed measures of OCRDs, depression, and worry before and after intensive/residential treatment for OCRDs. Structural equation modeling was used to examine the comorbidity structure and temporal course of the symptoms. Results Covariation of the symptoms was best represented by three dimensions: distress (depression and worry), compulsivity (obsessive–compulsive disorder, hoarding, and body dysmorphia), and grooming (hair pulling and skin picking). Latent change score modeling revealed significant reduction in the means of all three dimensions across treatment (Cohen's ds = −1.04, −0.62, and −0.23 for distress, compulsivity, and grooming, respectively). There was a strong correlation between change in compulsivity and grooming (r = .67) and change in compulsivity and distress (r = .80), but a small correlation between change in grooming and distress (r = .35). Conclusions The results indicate that OCRDs are underpinned by higher order compulsivity and grooming dimensions that differ in their association with distress. The results further suggest that the two dimensions may reflect promising intervention targets suitable for transdiagnostic treatment protocols.