An examination of the characteristics and mechanisms underlying contamination aversion

Abstract

Obsessive-compulsive disorder (OCD) is characterised by intrusive obsessions and compulsions. The contamination subtype of OCD, featuring obsessions about contamination and cleaning compulsions, is one of the most common presentations. Contamination aversion is often experienced in contamination OCD. Contamination aversion refers to the negative feeling and response evoked by a threat of contamination. It is influenced by a range of factors, including disgust, dysfunctional beliefs, magical thinking, information processing biases and emotion dysregulation. Recently, it has been proposed that this can be integrated into a two component model, whereby an affective component is driven by disgust and a cognitive component produces an appraisal based on various cognitive factors. Early studies suggest these components interact to process a threat, but they also differ in a range of areas, including the type of threat they predominantly process, the temporal stage of processing and the motivation of avoidance. However, much remains to be examined about the two components in terms of the responses produced, characteristics of processing and the effects of treatment. This thesis aims to examine responses to various contaminants in order to understand the two components of contamination aversion. The contaminants studied are: 1) direct contaminants, which are directly associated with disease, such as faeces; 2) indirect contaminants, which are threats indirectly associated with disease, such as money; and 3) harm contaminants, which are threats that have dangerous or harmful properties, such as asbestos. These contaminants are thought to be processed predominantly by either the affective or cognitive component, thus examining responses to these contaminants will provide information about how each component functions. These studies support the two component model of contamination. They provide information about similarities and differences between the two components and responses to treatment approaches. Theoretical and clinical implications are discussed.

Date of Award	2018
Original language	English