Major depression is a common disorder among non-professional caregivers, and it can be disabling and costly. Although there are effective psychological interventions to prevent depression, most of them involve in-person treatment. New technologies have the potential to overcome the barriers this format presents, which limit accessibility to such interventions. The main objective of this project is to evaluate the effectiveness of a cognitive-behavioral intervention in the prevention of depression, administered through a smartphone application (App), both with and without telephone contact through multiconferencing. Secondary objectives are: (a) test the moderating or mediating effect of the variables in the theoretical model underlying the intervention; (b) analyze the variables that are predictors of intervention outcomes; (c) analyze the acceptability and satisfaction with interventions. A randomized controlled trial will be perform. Caregivers with clinically significant depressive symptoms who do not meet the diagnostic criteria for depressive episode will be included. Recruitment of 174 participants is planned, with random allocation to one of the three conditions (58 participants per intervention): (a) a cognitive-behavioral intervention administered via a smartphone App (CCIA); (b) a cognitive-behavioral intervention administered via a smartphone App + telephone contact via conference call (CCIA+CC); (c) attention control group (ACG). Both interventions will be administered in 5 modules via an App for Smartphones and one group additionally will receive telephone contact via conference call in group format during 4 sessions of 30 minutes. These phone sessions will be recorded to assess the therapists adherence to the intervention protocols. All participants will be evaluated at pre and posttreatment, and 1-, 3-, 6- and 12-month follow-up by trained interviewers who will be blind to the aims of the study, the interventions employed, and the group to which any given participant belongs. Incidence of depression will be examined as the primary measure, with secondary measures being depressive symptoms, symptoms related to the model (pleasant activities, negative thoughts and social contacts) and the acceptability of and satisfaction with the intervention.