Predictors of outcome in self-guided internet-delivered cognitive-behavior therapy for obsessive-compulsive disorder: A preliminary investigation.

Internet-delivered cognitive-behavioral therapy (ICBT) is an effective treatment for obsessive-compulsive disorder (OCD). ICBT can be delivered in a self-guided or clinician-guided format. While a literature is emerging on the predictors of response to clinician-guided ICBT, there is a lack of research examining the predictors of response to self-guided ICBT. The aim of the present study was to examine predictors of outcome in a large sample of participants with OCD who commenced a self-guided ICBT intervention. One hundred and fifty-seven participants (M age  = 34.82; SD = 10.49; 78% female) were included in the study. Regression analyses were conducted to determine clinical and demographic predictors of (1) posttreatment symptom severity and (2) a clinically meaningful treatment response for both the intention-to-treat (ITT) and completer samples. The regression models significantly predicted posttreatment outcome for both the ITT (F (8, 148)  = 15.844, p < .001) and completer sample (F (8, 101)  = 5.929, p < .001), explaining 46% and 34% of the variance respectively. Higher baseline OCD severity, younger age, experiencing higher contamination or symmetry symptoms, and a history of past treatment were all found to be significantly associated with higher posttreatment severity in the ITT sample. In the completer sample only higher baseline OCD severity and severity of harm-related obsessions and checking compulsions was significantly associated with higher posttreatment severity. When predicting treatment response the regression models for both the ITT and completer sample were nonsignificant.