Brief Telephone Psychological Intervention for Depressive Symptoms in Caregivers

The presence of a major depressive episode will be assessed with the Structured Clinical Interview for Axis I Disorders from the Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV Clinical Version (Structured Clinical Interview for DSM-IV, Clinician Version [SCID-CV]; First, Spitzer, Gibbon and Williams, 1997/1999). This is a semi-structured interview that provides a DSM-IV diagnosis and must be administered by a clinician. It consists of six modules of diagnostic interviews: mood episodes, psychotic symptoms, psychotic disorders, mood disorders, substance use disorders, anxiety disorders, and other disorders. The SCID-CV has good test-retest reliability and adequate reliability for psychiatric patients (kappa index = 0.61)

Depressive symptoms as measured by the Center for Epidemiological Studies Depression Scale [CES-D] (Radloff, 1977; Spanish version of Vazquez, White, and 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).

Socio-demographic characteristics were collected via the Care Characteristics and Status of Caregiver questionnaire that was developed in a previous study (Vazquez et al., 2014). The data of caregivers (sex, age, marital status, number of children, social class, family monthly income per household, level of education, main occupation, province and area of residence), the care situation, health of the caregiver, and contact information (landline home phone)

The occurrence of automatic negative thoughts will be assessed through the 30-item Automatic Negative Thoughts Questionnaire (ATQ-N, Hollon and Kendall, 1980). The subject must indicate the frequency for which a number of thoughts have suddenly arisen in their mind over the last week on a five-point scale from 1 (never) to 5 (always). Scores range between 30 and 150, and there is a direct relationship between the score and the frequencies of certain types of thoughts, with a higher score indicating more negative thoughts experienced by the subject. The internal consistency for the ATQ-N subscale is .96.

To assess behavioral activation, we will use the Environmental Reward Observation Scale (EROS, Armento and Hopko, 2007; Spanish version Barraca and Pérez-Álvarez, 2010). It is a self-administered 10-item scale that assesses the degree of positive reinforcement contingent on the response received from the media. Each item is evaluated based on the degree to which the individual believes applies to them, according to a Likert scale with four response options ranging from 1 (strongly disagree) to 4 (strongly agree), with higher scores indicating a greater degree of positive reinforcement. The total score ranges from 10 to 40. The Spanish version of EROS is reliable (Cronbach's alpha = .86) and valid (high correlations with the BDI-II, BADS, STAI-S/R, AAQ, significant differences between participants and non-clinical subjects).

To evaluate the participants' weekly social contacts we will use the Register of Social Networking (developed and used in the previous study by Vazquez et al., 2014) that asks the participants to report the number of people they had daily contact with.

Self-efficacy will be evaluated with the 10-item version of the General Self-Efficacy Scale (GSES, Jerusalem and Schwarzer, 1992; Spanish version Baessler and Schwarzer, 1996). This self-administered 10-item scale was designed to assess the feeling of personal competence to deal with difficult life situations. Each item is evaluated based on the degree to which the subject believes that the statement about their ability to solve problems is true on a Likert 4-point scale ranging from 1 (false) to 4 (true). Higher scores indicate a greater expectation of self-efficacy. Internal consistency for the Spanish version, estimated by Cronbach's alpha was .81.

We will construct a registry of dropouts from each group to assess their response to the interventions over the duration of the study. In addition, treatment adherence will be assessed by recording the number of meetings each caregiver attends and whether they complete homework assignments.

Participant satisfaction with the service received will be evaluated upon intervention completion. We will use the Client Satisfaction Questionnaire ([CSQ-8]; Larsen, Attkisson, Hargreaves, and Nguyen, 1979; Spanish version Vazquez, Torres, and Otero, 2009). It is an 8-item scale with 4 possible answers and a final ranking score ranging from 8 to 32, where a higher score implies greater satisfaction with the service received. It is a widely used tool with an internal consistency between .83 and .93 (Attkisson and Greenfield, 2004).