Rumination About Obsessive Symptoms and Mood Maintains Obsessive-Compulsive Symptoms and Depressed Mood: An Experimental Study

Rumination is common in individuals diagnosed with obsessive-compulsive disorder (OCD). We sought to clarify the causal role of rumination in the immediate and intermediate maintenance of obsessive-compulsive symptoms and depressed mood. In total, 145 individuals diagnosed with OCD were asked to read aloud their most distressing obsessive thought (OT). OT activation was followed by a thought-monitoring phase in which frequency of the OT was assessed. Participants were randomly allocated to one of three experimental conditions: rumination about obsessive-compulsive symptoms, rumination about mood, or distraction. Ratings of distress, urge to neutralize, and depressed mood and frequency ratings of the OTs were taken before and after the experimental manipulation. Obsessive-compulsive symptom severity and affect were assessed 2, 4, and 24 hr after the laboratory experiment using ecological momentary assessment. Compared to distraction, both types of rumination resulted in an immediate reduced decline of distress, urge to neutralize, depressed mood, and frequency of OTs, with medium to large effect sizes. Rumination about obsessive-compulsive symptoms did not have a stronger immediate effect than rumination about mood. Rumination about obsessive-compulsive symptoms increased obsessive-compulsive symptom severity and reduced positive affect compared to rumination about mood 24 hr later. Regarding negative affect, there was no difference in effect between the two types of rumination in the intermediate term. To conclude, rumination in OCD has an immediate and intermediate maintaining effect on obsessive-compulsive symptoms and mood and may require additional psychological interventions that supplement cognitive behavioral therapy.