Randomised controlled trial of cognitive behaviour therapy versus mindfulness for people with rheumatoid arthritis with and without a history of recurrent depression: study protocol and design.

Introduction: Psychosocial treatments have been shown to benefit people with rheumatoid arthritis (RA) on various outcomes. Two evidence-based interventions are cognitive behavioural therapy (CBT) and mindfulness-based stress reduction (MBSR). However, these interventions have been compared only once. Results showed that CBT outperformed MBSR on some outcomes, but MBSR was more effective for people with RA with a history of recurrent depression, with efficacy being moderated by history of depressive episodes. However, this was a post-hoc finding based on a small subsample. We aim to examine whether a history of recurrent depression will moderate the relative efficacy of these treatments when delivered online.

Methods And Analysis: This study is a randomised controlled trial comparing CBT and MBSR delivered online with a waitlist control condition. History of recurrent depressive episodes will be assessed at baseline. The primary outcome will be pain interference. Secondary outcomes will include pain intensity, RA symptoms, depressive symptoms and anxiety symptoms. Outcome measures will be administered at baseline, post-treatment and at 6 months follow-up. We aim to recruit 300 participants, and an intention-to-treat analysis will be used. Linear mixed models will be used, with baseline levels of treatment outcomes as the covariate, and group and depressive status as fixed factors. The results will demonstrate whether online CBT and MBSR effectively improve outcomes among people with RA. Importantly, this trial will determine whether one intervention is more efficacious, and whether prior history of depression moderates this effect.

Ethics And Dissemination: The trial has been approved by the Human Research Ethics Committee of the University of Sydney (2021/516). The findings will be subject to publication irrespective of the final results of the study, and based on the outcomes presented in this protocol.

Trial Registration Number: Australian New Zealand Clinical Trials Registry (ACTRN12621000997853p).