RESUMEN
OBJECTIVES: The current study evaluated the feasibility of an internet-delivered cognitive therapy (I-CT) in a self-help format with minimal therapist support for patients with obsessive-compulsive disorder (OCD) with primary taboo obsessions. Specifically, the aims were to investigate (1) whether participants were able to grasp and apply the internet-delivered cognitive framework to their own situation; (2) whether they had clinically meaningful reductions of OCD symptom severity; and (3) whether reduced negative appraisals (hypothesized mechanism of change in CT) preceded reductions in OCD symptom severity. METHOD: Nineteen OCD patients with primary taboo obsessions, recruited from an OCD clinic or self-referrals, received the I-CT intervention for 10 weeks. I-CT did not contain any systematic exposure or response prevention. RESULTS: Adherence and engagement with the intervention was high. Most participants (n = 13, 68%) understood and successfully applied the cognitive model to their own situation. Within-group analyses showed large reductions in OCD symptom severity at post-treatment (bootstrapped within group d = 1.67 [95% CI; 0.67 to 2.66]) measured with the Yale-Brown Obsessive-Compulsive Scale. The gains were maintained at the 6-month follow-up. Post-hoc analyses revealed that the large reductions in OCD symptom severity were driven by the participants who understood the cognitive model. Reductions in negative appraisals predicted subsequent reductions in OCD symptom severity during treatment. CONCLUSION: It is possible to adapt a purely cognitive intervention to a digital guided self-help format and to achieve both cognitive change and meaningful symptom reduction. The results require confirmation in a randomized clinical trial.