The Quantification of Doubt in Obsessive-Compulsive Disorder

Obsessive-Compulsive Disorder (OCD) is a debilitating psychiatric disorder characterized by high levels of pathological doubt. The current article investigates the cognitive process of doubt in OCD as the dynamic interplay between the impact of possibility and reality-based information. An experimental reasoning task was designed to measure changes in level of doubt by alternately presenting participants with possibility and reality-based information. People with OCD were hypothesized to be more affected by possibility-based information leading to higher levels of doubt. Results confirmed these expectations, and showed that as compared to nonclinical controls, those with OCD were more affected by possibility-based information. The impact of possibility-based information, and levels of doubt, related robustly to symptom severity. As expected, the relationship between the impact of possibility and symptom severity could be explained by inferential confusion, but not by any other cognitive domains, thereby confirming the convergent validity of the current experimental manipulation.