Role of perceived danger in the mediation of obsessive-compulsive washing

The role of danger expectancies in sub-clinical Obsessive-Compulsive Disorder (OCD) was examined in 18 undergraduate students who had displayed washing/contamination concerns. The perceived level of danger in a Behavioural Avoidance Test (BAT) involving a compound stimulus of potting soil, animal hair, food scraps, and raw meat was manipulated by varying the instructions participants were given at the commencement of the BAT. Participants were randomly allocated into a high-danger instruction condition or a low-danger instruction condition. Participants in the higher-danger instruction condition had higher mean ratings for anxiety and urge in wash, showed greater avoidance, and spent longer washing their hands at the completion of the task than participants in the low-danger instruction condition. However, only the differences in avoidance scores and post-BAT washing were statistically significant. These findings are discussed in relation to danger-based models of OCD.