The Place of Obsessive-Compulsive and Related Disorders in the Compulsive-Impulsive Spectrum: A Cluster-Analytic Study.

Background The extent to which obsessive-compulsive and related disorders (OCRDs) are impulsive, compulsive, or both requires further investigation. We investigated the existence of different clusters in an online nonclinical sample and in which groups DSM-5 OCRDs and other related psychopathological symptoms are best placed. Methods Seven hundred and seventy-four adult participants completed online questionnaires including the Cambridge-Chicago Compulsivity Trait Scale (CHI-T), the Barratt Impulsiveness Scale (BIS-15), and a series of DSM-5 OCRDs symptom severity and other psychopathological measures. We used K-means cluster analysis using CHI-T and BIS responses to test three and four factor solutions. Next, we investigated whether different OCRDs symptoms predicted cluster membership using a multinomial regression model. Results The best solution identified one "healthy" and three "clinical" clusters (ie, one predominantly "compulsive" group, one predominantly "impulsive" group, and one "mixed"-"compulsive and impulsive group"). A multinomial regression model found obsessive-compulsive, body dysmorphic, and schizotypal symptoms to be associated with the "mixed" and the "compulsive" clusters, and hoarding and emotional symptoms to be related, on a trend level, to the "impulsive" cluster. Additional analysis showed cognitive-perceptual schizotypal symptoms to be associated with the "mixed" but not the "compulsive" group. Conclusions Our findings suggest that obsessive-compulsive disorder; body dysmorphic disorder and schizotypal symptoms can be mapped across the "compulsive" and "mixed" clusters of the compulsive-impulsive spectrum. Although there was a trend toward hoarding being associated with the "impulsive" group, trichotillomania, and skin picking disorder symptoms did not clearly fit to the demarcated clusters.