Appraisal-based cognitive bias modification in patients with posttraumatic stress disorder: a randomised clinical trial

Background: Negative appraisals of the trauma and its sequelae play a crucial role in the development and maintenance of Posttraumatic Stress Disorder (PTSD). Experimental studies have shown promise in reducing negative appraisal through Cognitive Bias Modification (CBM) training. Objective: To determine whether an online CBM training designed to modify dysfunctional appraisals is successful in reducing appraisal bias in PTSD patients. Method: In this double-blinded 2-arm randomised clinical trial, 107 patients with PTSD were randomly allocated to active (n = 49) or control online CBM training (n = 57). Training comprised the completion of four sessions of online CBM training within one week. Change in bias, as measured by a scenario task and questionnaire (i.e. PostTraumatic Cognition Inventory), was the primary outcome. Secondary outcome included change in PTSD symptoms. Assessments took place prior to training, during training sessions, post-training and at 1- and 6-month follow-up. Results: Intent-to-treat analysis indicated that there was no interaction effect of condition by time. Regardless of training condition, participants showed a small to moderate decline in appraisal bias and PTSD symptoms from pre- to post-training. In both conditions, bias change during training sessions was related to decline in PTSD symptomatology following training. No moderators of outcome were found. Conclusions: There was no evidence that active training was more effective than control training in reducing dysfunctional appraisals. In both conditions, participants showed a decline in dysfunctional appraisals and PTSD symptoms following training. Importantly, bias reduction during training was related to PTSD symptom decline following training. Explanations and future research directions are discussed.