Objective: To evaluate the efficacy of an adjuvant intervention based on a peer support program in the reduction of depressive symptomatology versus an online intervention in people with major depression in Primary Care Mental Health Units in Mallorca.

Design: Randomized clinical trial of two branches in a Mental Health Unit of Mallorca, where one branch will receive an adjuvant intervention based on a peer support program (Active Patient Program) and another branch (control) will receive information and exercises aimed at improving their mental health through the COGITO App, designed and validated for this purpose. Scope and study subjects: The scope of the study will be the consultations of the Mental Health Unit (MHU) of Primary Care in Mallorca. The study subjects will be patients of these units who meet the criteria for Major Depression. The mental health professionals of the MHU will be in charge of recruiting participants who meet the inclusion and exclusion criteria. The required sample will be 70 subjects, 35 in each branch. Variables: The main dependent variable is depressive symptomatology, measured through the Beck Depression Inventory (BDI-II). As secondary variables, quality of life and adherence to treatment will be included. Data analysis: All analyses will be carried out using the SPSS statistical program. An intention-to-treat (ITT) analysis will be performed. The efficacy of the intervention (reduction of depressive symptoms (BDI-II)) will be assessed by a general linear model (ANOVA) at 6 weeks, 6 and 12 months, adjusted for baseline values.