Effect of Treatment Augmentations Embedded in Behavioural Activation Group Therapy on Reducing Drop-out and Stasis Rates in Depression

Depression is one of the most common mental health disorders and it is estimated up to 50% of patients do not respond to evidenced-based psychotherapy treatment, recording a 'stasis' outcome. However, there is limited research understanding this population, meaning a considerable number of people continue to suffer. The purpose of this study is to 1) identify depression stasis prevalence and predictors in an existing evidenced-based group treatment for depression, 2) run a clinical trial to test whether an embedded intervention based on theoretical and clinical practice evidence can help reduce patient depression stasis and drop-out rates and 3) understand what aspect of therapy produces change (or prevents change in stasis). The study will be based on behavioural activation (BA) therapy delivered in an eight-session group format in an Improving Access to Psychological Therapies (IAPT) service in the United Kingdom. BA is one of the most effective psychotherapies available for depression and focuses on helping patients to increase their engagement with valued activities to help break out of the cycle of depression. Firstly, an archived anonymised dataset of routine depression measures from patients who have previously received the existing group BA treatment will be analysed. Secondly, the group BA treatment delivered to patients in 2017 will be enhanced with two treatment augmentations. One augmentation will target stasis outcomes through the addition of specific 'if-then' planning (known as implementation intentions) when setting between-session homework and the other augmentation will target patient drop-out by informing patients about group BA effectiveness and therapy-dose evidence. The stasis outcomes and drop-out rates from the enhanced treatment in the trial will be compared with the archived outcomes to see if the intervention has had an effect and the role of engaging in valued living as a mechanism of change for depression symptoms will be examined. It is hypothesised that a) 50% of patients who have received the existing BA group treatment for depression will have a stasis outcome, b) there will be a significant reduction in depression stasis outcomes and drop-out rate following the enhanced BA group treatment delivered in the trial and c) engagement in valued living will have a mediating effect on outcome for responding patients following the enhanced BA group treatment but the effect will not be present for patients with a stasis outcome.