Protocol for a randomized controlled dismantling study of an internet-based intervention for depressive symptoms: exploring the contribution of behavioral activation and positive psychotherapy strategies

Background: there are evidence-based interventions for depression that include different components. However, the efficacy of their therapeutic components is unknown. Another important issue related to depression interventions is that, up to now, their therapeutic components have only focused on reducing negative symptoms rather than on improving positive affect and well-being. Because the low levels of positive affect are more strongly linked to depression than to other emotional disorders, it is important to include this variable as an important treatment target. Positive psychotherapeutic strategies (PPs) could help in this issue. The results obtained so far are consistent and promising, showing that Internet-based interventions are effective in treating depression. However, most of them are also multi-component, and it is important to make progress in investigating what each component contributes to the intervention. Methods: the current study will be a three-armed, simple-blinded, randomized controlled clinical trial with a dismantling design. 192 participants will be randomly assigned to: a) an Internet-based Global Protocol condition, which includes traditional therapeutic components of evidence-based treatments for depression (Motivation for change, Psychoeducation, Cognitive Therapy, Behavioral Activation (BA), Relapse Prevention) and PPs component, offering strategies to enhance positive mood and promote psychological strengths; b) an Internet-based BA Protocol condition (without the PPs component), and c) an Internet-based PPs Protocol condition (without the BA component). Primary outcome measures will be the BDI-II and PANAS. Secondary outcomes will include other variables such as depression, anxiety and stress, quality of life, resilience, and wellbeing related measures. Treatment acceptance and usability will also be measured. Participants will be assessed at pre-, post-treatment, 3-, 6- and 12- month follow- ups. The data will be analyzed based on the Intention-to-treat principle. Per protocol analyses will also be performed. Discussion: to the best of our knowledge, this is the first randomized dismantling intervention study for depression with the aim of exploring the contribution of a PPs component and the BA component in an Internet-based intervention. The three protocols are online interventions, helping to reach many people who need psychological treatments and otherwise would not have access to them