Has science found the source of OCD?

To better understand the root of obsessive-compulsive disorder, researchers used a behavioural model. Ideally, memory trace signals for past actions decay at equal speed for both positive and negative prediction errors. Using simulations, NAIST scientists found that agents implicitly learn obsessive-compulsive behavior when the trace decay factor for memory traces of past actions related to negative prediction errors is much smaller than that related to positive prediction errors. This means that, from the opposite perspective, the view of past actions is much narrower for negative prediction errors than for positive prediction errors. "Our model, with imbalanced trace decay factors successfully represents the vicious circle of obsession and compulsion characteristic of OCD," say co-first authors Yuki Sakai and Yutaka Sakai.