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. CBM training aimed at reducing negative appraisals yielded promising findings in clinical analogue samples* In this RCT, active CBM training did not lead to a greater decline in dysfunctional appraisals than control training.* This study highlights the impact of appraisal on PTSD symptoms: irrespective of training condition, bias reduction during training was related to lower PTSD symptoms following training. * Follow-up studies are needed to further explore the possible clinical efficacy of CBM interventions in PTSD.