Improvement in Distress Tolerance as a Mechanism of Symptom Reduction During Intensive Exposure and Response Prevention- Based Treatment for OCD

Exposure and Response Prevention (ERP) is an effective treatment for obsessive-compulsive disorder (OCD), yet the specific underlying mechanisms by which ERP improves symptoms remain unclear. Initial theories suggested that habituation to triggering events and stimuli was the key therapeutic factor in ERP, while other theories highlight the role of developing the ability to tolerate distress, rather than reduction of distress. The current study examined improvements in distress tolerance as a mechanism of OCD, anxiety, and depressive symptom reductions during an ERP-based intensive program. Participants (N = 180) completed weekly measures of distress intolerance, and symptom severity of OCD, anxiety, and depression. Using Multi-Level Structural Equation Modeling, we found that participants experienced significant weekly decreases in OCD, anxiety, and depressive symptom severity across the course of their ERP-based treatment. Weekly reductions in OCD symptom severity were partially accounted for by weekly improvements in participants' ability to tolerate distress, particularly for obsession symptoms. This effect was also significant for anxiety and depressive symptom severity, above and beyond the effects of weekly reductions in OCD symptom severity. The current study suggests improving the ability to tolerate distress represents a transdiagnostic mechanism of symptom severity reduction in OCD, anxiety, and depressive psychopathology via intensive ERP-based psychotherapy programming. Limitations and future directions for improving treatments for OCD, anxiety, and depressive symptoms are discussed.