A factorial randomized controlled trial on internet-delivered combined cognitive bias modification in people with high obsessive-compulsive disorder symptoms

The current study aimed to examine the effectiveness of internet-delivered Combined Cognitive Bias Modification (iCBM-C) for interpretation (CBM-I) and attention (CBM-A) for obsessive-compulsive disorder (OCD) symptoms comparatively.Eighty-two participants (mean age = 26.5, SD = 5.93; 79.3% female) with high OCD symptoms were randomly assigned to eight sessions of iCBM-C (n = 22), iCBM-I, (n = 20), iCBM-A (n = 20), or wait-list control (WLC) (n = 20). Assessments of OCD symptoms and beliefs, depression, anxiety, stress, and mood were administered at baseline, post-intervention at week 4 and 1-month follow-up, whereas assessments of interpretation and attentional biases were administered at baseline and post-intervention at week 4. Both iCBM-C and iCBM-I reduced OCD beliefs compared to the iCBM-A, and negative OC-relevant interpretations compared to both iCBM-A and WLC at post-intervention at week 4, with no clear superiority of one intervention over the other. Although both the interventions also reduced OCD symptoms, only iCBM-I was superior to WLC at post-intervention at week 4. There were no differences between groups regarding attentional bias, depression, anxiety, stress, and mood at post-intervention at week 4. There were also no differences between groups in terms of any outcome at 1-month follow-up. Although our findings provide further evidence for the utility of CBM-I for OCD, iCBM-C also revealed promising outcomes. Should these findings be replicated in specific subgroups, iCBM-C has the potential to be accessible and effective treatment for OCD.