The mediating roles of disgust sensitivity and danger expectancy in relation to hand washing behaviour.

BACKGROUND Recent interest in the role of vulnerability factors in obsessional washing has suggested that disgust sensitivity, danger expectancy and health anxiety may be of interest. AIMS This study explores the differential impact of these factors on both behavioural and cognitive measures of washing behaviour and is based on a replication of the Jones and Menzies (1997) experiment, during which participants immersed their hands in a noxious compound while rating themselves on a range of measures: the time they subsequently took to wash their hands was measured and danger expectancies were found to be the best predictor of this. METHOD The present study added measures of disgust sensitivity and health anxiety to this experimental methodology while removing factors they found to be of little import to compulsive washing. Thirty non-clinical participants took part. RESULTS Results confirmed that disgust sensitivity was related to the behavioural measure of washing time, but that this relationship was almost entirely mediated by the danger expectancy concerning judgements of severity of consequent disease. However, a different pattern emerged when the outcome measure was questionnaire based: danger expectancy was not at all related to this. Disgust sensitivity mediated the relationship between health anxiety and scores on a questionnaire measure of washing compulsions. Interestingly, these scores were not related to the behavioural measure of washing time. CONCLUSIONS The implications of these relationships to the further development of subtypes of Obsessive Compulsive Disorder (OCD) are discussed.