The Impact of Modifying Interpretive Bias on Contamination-Related Obsessive–Compulsive Symptoms

Cognitive-behavioural models of obsessive–compulsive disorder (OCD) propose that a tendency to negatively interpret ambiguous thoughts and situations plays a key role in maintaining the disorder. Moreover, some researchers have proposed that negative interpretive biases may share a common processing mechanism with attentional biases, with changes in one predicted to lead to changes in the other. The current study examined whether training positive (i.e., adaptive) interpretive bias of contamination-related OCD concerns using a cognitive bias modification paradigm (CBM-I) would lead to reductions in contamination concerns, as well as changes in contamination-related attentional bias. Undergraduate students with high levels of contamination-related OCD symptoms were randomly assigned to receive either positive (n = 31) or neutral (n = 33) CBM-I training. Participants in the positive training condition, relative to the neutral training condition, showed a significantly greater increase in positive interpretive bias, significantly less within-session behavioural avoidance of contaminants, and significantly reduced contamination-related cognitions (at one-week follow-up). Contrary to expectations, CBM-I training did not differentially impact attentional bias nor self-reported contamination-related OCD symptoms. We discuss future directions in applying CBM-I to contamination-related OCD.