Moderators of outcome in self-guided internet-delivered cognitive-behavior therapy for obsessive-compulsive disorder.

Internet-delivered cognitive behavioural therapy (ICBT) is an effective treatment for obsessive-compulsive disorder (OCD). Currently there is limited research examining the predictors and moderators of outcome in ICBT for OCD. This study examined moderators of treatment outcome in a sample of 216 individuals who commenced a self-guided ICBT intervention for OCD (Mage = 34.00; SD = 12.57; 72.7% female). The results indicated that those with higher baseline OCD severity, depression severity, and neuroticism had less improvement at post-treatment and follow up (resulting in 40%, 24% and 12% higher symptom severity for every standard deviation increase on the measure at post-treatment and 33%, 17% and 20% higher symptoms at follow up respectively). However, participants with higher baseline treatment expectancy and readiness to reduce rituals and compulsions had better outcomes at post-treatment and three-month follow up (resulting in a 5% and 7% lower symptom severity for every standard deviation increase on the measure at post-treatment and 12% and 12% lower symptoms at follow up respectively). The results have important implications for who may respond best to self-guided ICBT.