Frequency and level of self-efficacy predict the effectiveness of therapist- and self-guided exposure in obsessive compulsive disorder.

BACKGROUND While exposure and response prevention (ERP) is the most effective treatment for obsessive compulsive disorder (OCD), less is known about the specific mechanisms underlying symptom change after ERP. AIMS We tested the hypothesis that the frequency of self- and therapist-guided ERP related to the extent of symptom reduction and that this link is mediated by increased self-efficacy. METHOD In a sample of 377 in-patients with a primary diagnosis of OCD receiving in-patient CBT, we assessed symptoms (YBOCS-SR) and self-efficacy (General Self-Efficacy Scale), before and after treatment, as well as the frequency of therapist- and self-guided ERP sessions. RESULTS Patients with more therapist-guided ERP sessions during treatment showed more symptom reduction and the association of self-guided ERP on outcome was mediated by enhanced self-efficacy. CONCLUSIONS These findings highlight the importance of both therapist- and self-guided ERP sessions and suggest that therapists should conduct a sufficient number of ERP sessions to optimise treatment.