Why check? A meta-analysis of checking in obsessive-compulsive disorder: Threat vs. distrust of senses.

Compulsive checking is the most common ritual among individuals with obsessive-compulsive disorder (OCD). Yet, other than uncertainty, the variables prompting checking are not fully understood. Laboratory studies suggest that task conditions - whether threatening (anxiety-relevant) or neutral, and task type - whether requiring perceptual or reasoning decision-making - may be influential. The purpose of our meta-analysis was to compare OCD participants and healthy controls on experimental tasks involving uncertainty in which a behavioral measure of checking was obtained. Four databases were searched. Twenty-two studies met the inclusion criteria, including 43 conditions comparing 663 OCD participants to 614 healthy controls. Due to the dependent structure of the data a robust variance estimation analysis approach was used. Overall effects were similar for neutral and threatening conditions. However, OCD participants responded with greater checking compared to controls on perceptual tasks, but not on reasoning tasks. Results support previous reports suggesting that OCD checking can be observed in neutral conditions, possibly posing as a risk factor for a checking vicious cycle. In addition, our results support OCD models which focus on checking as stemming from interference with automatic processes and distrust of sensory modalities.