Obsessive Compulsive and Related Disorders
Is disgust proneness an endophenotype for OCD? A self-report examination of individuals with OCD, their first-degree relatives, and healthy controls
Sarah C. Jessup, M.A.
Graduate Student
Vanderbilt University
Nashville, Tennessee
Bunmi O. Olatunji, Ph.D.
Professor
Vanderbilt University
Nashville, Tennessee
Obsessive-compulsive disorder (OCD) is characterized by distressing, persistent thoughts and/or repetitive behaviors and affects approximately 2 to 3% of the population (Slade et al., 2009). Disgust proneness has been consistently implicated in the development and maintenance of OCD. Many studies have found significant, positive associations between disgust proneness and OCD symptoms, even after controlling for negative affect (e.g., Olatunji, Ebesutani et al., 2011; Olatunji, Ebesutani et al., 2017). Although disgust proneness appears to play a critical role in OCD, it remains unclear whether this represents an OCD endophenotype. That is, disgust proneness may be heritable and present even when the disorder is not present, such that non-affected family members also experience higher levels of disgust proneness compared to the general population (Gottesman & Gould, 2003). The present study is the first to examine disgust as a potential endophenotype for OCD. Adults (N = 82) with OCD who endorsed at least moderate current symptom levels on the Yale-Brown Obsessive-Compulsive Scale (Goodman et al., 1989) including contamination fears, and identified a first-degree relative who was also willing to participate were recruited. There were three groups in the study: individuals with OCD (n = 29), their first-degree relatives (n = 28), and age-matched healthy controls (n = 25). Participants completed a series of self-report measures including the Disgust Propensity and Sensitivity Scale-Revised (DPSSR; van Overveld et al., 2011), the Contamination-Cognitions Scale (CCS; Deacon & Olatunji, 2007), and the Obsessive-Compulsive Inventory-Revised (OCI-R; Foa et al., 2002). Results revealed that the OCD group reported significantly higher levels of disgust proneness and contamination cognitions than their first-degree relatives and healthy controls (all ps < .001). Contrary to predictions, the first-degree relatives and healthy controls did not significantly differ in self-reported disgust proneness or contamination cognitions (ps > .10). For all three groups, there was a significant, moderate positive correlation between disgust proneness and contamination cognitions, and also between disgust proneness and OC washing symptoms (ps < .01). However, disgust proneness was not significantly associated with other OC symptom subtypes across all three groups. Although these findings suggest that disgust proneness may not function as a distinct endophenotype for contamination OCD, heightened levels of disgust proneness do appear to more strongly and selectively predict the contamination obsessions and washing compulsions that are commonly observed in OCD. These findings will be discussed in light of the disease-avoidance function of disgust.