Expectancy bias for disgust and emotional responding in contamination-related obsessive-compulsive disorder

The present study examines the relation between disgust and contamination-related obsessive-compulsive disorder symptoms (OCD) in an analog sample. The results showed that disgust sensitivity is significantly correlated with contamination-related OCD. Participants high in contamination OCD (HOCD) generally report significantly more disgust than low contamination-related OCD (LOCD) participants. We also examined if differential disgust UCS expectancies exists in contamination OCD using a thought experiment. Participants estimated the probability that fear, disgust, and neutral stimuli (conditioned stimuli) would be followed by a fear, disgust, or neutral facial expression (unconditioned stimuli) in the thought experiment. Although no significant differences were found between the two groups on expectancies for disgust outcomes to be associated with disgust-relevant stimuli, HOCD participants showed a marginal bias towards overestimating the occurrence of disgust outcomes to be associated with fear-relevant stimuli, while underestimating the occurrence of disgust outcomes to be associated with neutral stimuli. HOCD participants also reported more fear and disgust to fear-relevant and disgust-relevant stimuli than LOCD participants. However, subsequent analysis revealed that disgust sensitivity mediated fear and disgust responding to threat stimuli. These findings highlight the potential importance of disgust in the phenomenology of contamination-related OCD.