The place of obsessive-compulsive and related disorders in the compulsive-impulsive spectrum: a cluster-analytic study

Abstract

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.

Keywords: Compulsivity; body dysmorphic disorder; hoarding disorder; impulsivity; obsessive–compulsive disorder; trichotillomania.

Figure 1. Scatterplot describing a three-cluster solution of the data with a mixed compulsive-impulsive (green) cluster, a predominantly compulsive (red) cluster and a healthy (blue) cluster.

Figure 2. K-means clustering from the three-cluster solution revealing individuals low in compulsivity and low in impulsivity (cluster 1), high in compulsivity and low in impulsivity (cluster 2) and high in impulsivity and high in compulsivity (cluster 3).

Figure 3. Scatterplot describing a four-cluster solution of the data with a mixed compulsive-impulsive (red) cluster, a predominantly compulsive (blue) cluster a predominantly impulsive (orange), cluster and a “healthy” (green) cluster.

Figure 4

K-means clustering from the four-factor solution? revealing individuals high in compulsivity (cluster 1), high in compulsivity and impulsivity (cluster 2), low in compulsivity and in impulsivity (cluster 3, “healthy”), and high in impulsivity and low in compulsivity (cluster 4).