Cognitive-behavior therapy (CBT) for obsessive-compulsive disorder (OCD) is a highly specialized treatment that is in short supply worldwide. This study aimed to investigate whether therapist-guided internet-delivered CBT (ICBT) is non-inferior to face-to-face CBT for adults with OCD. Secondary objectives were to investigate if ICBT could be equally effective without therapist support (i.e. unguided), to conduct a health-economic evaluation, and to determine whether treatment effects were moderated by source of participant referral.
A consecutive sample of 120 adults with a primary diagnosis of OCD, either self-referred or referred by a clinician, were randomized to receive guided ICBT (n=42), unguided ICBT (n=40) or face-to-face CBT (n= 38) delivered over 14 weeks. The main outcome measure was change in OCD symptom severity according to the clinician rated Yale-Brown Obsessive Compulsive Scale (Y-BOCS) from baseline to 3-month follow-up (primary endpoint). The non-inferiority margin was set to 3 points on the Y-BOCS.
Results: Of the 120 randomized participants, 80 (67%) were women with a mean age of 32 (SD = 9.64) years.The mean difference between therapist-guided ICBT and face-to-face CBT at the primary endpoint was 2.10 points on the Y-BOCS (90% CI -0.41 to 4.61), P = .17, favoring face-to-face CBT, meaning that the primary non-inferiority results were inconclusive. The difference between unguided ICBT and face-to-face CBT was 5.35 points (90% CI 2.76 to 7.94), P < .001), favoring face-to-face CBT. The health economic analysis showed that both guided and unguided ICBT were cost-effective compared to face-to-face CBT. Source of referral did not moderate treatment outcome. The most common adverse events were anxiety (25%), depressive symptoms (17%) and stress (9%).
Conclusions and Relevance: In this randomized controlled trial of internet-based versus face-to-face cognitive behavioral therapy for adults with obsessive-compulsive disorder we could not conclusively demonstrate non-inferiority. Therapist-guided ICBT could be a cost-effective alternative to in-clinic CBT for adults with OCD in scenarios where traditional CBT is not readily available. Unguided ICBT is probably less efficacious but could be an alternative when providing remote clinician support is not feasible.