The participants of the two experimental groups will receive a cognitive-behavioral intervention for depression prevention via a smartphone App, adapted from an indicated depression prevention program for caregivers in face-to-face group format developed by our research team, based on the model by Lewinsohn, Hoberman, Teri, & Hautzinger (1985), which has proven to be efficacious in the prevention of the onset of new major depressive episodes and the decrease of depressive symptoms both short- and long-term (Vázquez et a., 2014, 2016). In both groups the intervention administered via App will consist of 5 modules.

Additionally, this experimental group will receive phone group conference calls during four 30 minute-sessions.

Individuals assigned to this group will receive no intervention or material, but they will have unrestricted access to any routine medical or psychological care that they might want to seek to treat depressive symptoms.The use of such treatments will be recorded.

Multicomponent Cognitive Behavioral Intervention administered via a smartphone App (CCIA)

The presence of a major depressive episode will be assessed with the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders-5, DSM-5® -Clinician Version (SCID-5-CV; First, Williams, Karg, & Spitzer, 2015). This is a semi-structured interview that provides DSM-5 diagnosis and must be administered by a specialized professional. It includes diagnostic assessment of depressive disorder, bipolar disorder, schizophrenia and other psychotic disorders, substance use disorders, anxiety disorders, obsessive-compulsive disorder, posttraumatic stress disorders, attention deficit and hyperactivity disorder, adaptative disorders, and it allows screening for 17 additional disorders. For this study the module corresponding to major depressive episode was use. The interrater reliability (Kappa) ranges from .70 y 1.00.

Depressive symptoms as measured by the Center for Epidemiological Studies Depression Scale [CES-D] (Radloff,1977; Spanish version of Vazquez, Blanco, & Lopez, 2007). This 20-item scale is self-administered and assesses depressive symptoms. The person evaluates each item based on how often they have experienced it in the last week using a Likert scale with four response options ranging from 0 (rarely or none of the time) to 3 (most of the time).The total score ranges from 0 to 60, and higher scores correspond to greater depressive symptomatology. Internal consistency (Cronbach's alpha) of the scale ranges from .85 and .90, with .89 for the Spanish version (Vazquez et al.,2007 and 2014).

Sociodemographic characteristics were collected via the Care Characteristics and Status of Caregiver questionnaire. This questionnaire was developed in a previous study (Vázquez et al., 2014, 2016), and assesses the sociodemographic characteristics (sex, age, marital status, social class, family monthly income per household, level of education, main occupation and area of residence), and the care situation (number of persons cared for, relationship with the persona cared for, age and sex of the person cared for, disease of the person cared for, time of care, and hours a day of care) of non professional caregivers.