Background: Depression is a common comorbidity of physical chronic diseases such as diabetes and/or hypertension and constitutes an important public health problem. It correlates negatively with the patients' quality of life and self-care, as well as compliance with medical treatment. In low- and middle-income countries depression often goes unrecognized and untreated, and there are limited human resources to treat depression and other mental problems.

Aim: The present study aims to test a 6-week low-intensity psychological intervention (CONEMO - CONtrol EMOcional) delivered by a smartphone application to people with depressive symptoms and co-morbid diabetes and/or hypertension recruited in primary health care centers and public hospitals in Lima, Peru.

Epidemiologic research has clearly established the significant public health importance of mental disorders in low- and middle-income countries (LMIC). Among mental disorders, depression has become a major problem as a single condition and, more often, as part of complex clinical settings in which multiple conditions and risk factors are combined.

There is substantial co-morbidity between depression and chronic physical conditions, and the outcome of both conditions is impaired when there is this co-morbidity. Most of the disease burden in Latin America is attributable to chronic diseases such as cardio-vascular diseases as hypertension and diabetes, as well as to mental disorders such as depression. Despite the public health impact of depression, it often goes unrecognized and untreated. One important factor for this treatment gap are the limited financial and human resources. The mental health resources available in LMIC are often not optimally distributed either. Funds and trained personnel are typically allocated to tertiary health care services, such as psychiatric hospitals.

Therefore, any short- and medium-term efforts to develop, evaluate, and disseminate effective mental health interventions in LMIC must adapt to these severe workforce shortages, resource limitations, and budgetary inequities. The mental health field needs to consider developing self-help automated interventions that can reach people where there is insufficient access to specialized health care providers. This can be partially addressed applying two strategies: 1) increasing effective self-management; and 2) task-shifting roles to less specialized but appropriately trained health workers.

The investigators are conducting a randomized controlled trial with individuals with chronic diseases, i.e. hypertension and/or diabetes, and symptoms of depression in primary health centers and hospitals in Lima, Peru. Participants will be randomly assigned to the control arm or the intervention arm. The later will receive the CONEMO intervention, monitored by nurses.

The focus of this project is on using a self-help intervention that provides advice, support, and motivation. However, studies suggest that depressed patients left alone with the devices fail to make good use of self-help interventions. Therefore, nurses will monitor participants by a web-based dashboard connected to the smartphone application (CONEMO), motivate to continue using CONEMO if participants are non-adherent and give technical support. Nurses will take part in supervision meetings at least once a week.

Method:

CONEMO is a randomized controlled trial conducted with 432 chronic patients who present diabetes and/or hypertension and depressive symptoms recruited in primary health care centers and public hospitals in Lima, Peru. Half of these participants will be randomized to receive the CONEMO intervention and the other half will receive enhanced usual care. The randomization will be made based on 2 strata: the health center/hospital the participant comes from and his/her PHQ9 score at screening (≤14; ≥15).

The intervention, based on behavior activation, is delivered by a smartphone and monitored by nurses who mediate this intervention, motivating and supporting the participant and monitoring his/her performance. The CONEMO intervention is delivered 3 times a week for a period of 6 weeks, summing up to a total of 18 sessions. Intensity of depressive symptoms is assessed by research assistants using the PHQ-9 at baseline, 3- and 6-month follow-up assessments.

Outcomes:

The primary outcome in this study is the proportion of participants with a reduction of 50% or more in the PHQ-9 score at the 3-month assessment. The secondary outcomes are the proportion of participants with a reduction of 50% or more in the PHQ-9 score at the 6-month assessment, and the improvement in quality of life, adherence to diabetes, level of activity and hypertension medication and social functioning. There will also be a cost-effectiveness evaluation using a intention to treat analysis, and a process evaluation. For the process evaluation, data will be collected from questionnaires about the CONEMO system, filled out by with participants at 3 months after inclusion, and interviews with the nurses at the end of the intervention.

Inclusion Criteria:

• Age 21 or older
• Presenting depressive symptoms (PHQ9≥10)
• Clinical diagnosis of diabetes and/or hypertension
• Able to read

Exclusion Criteria:

• If pregnant, the diagnosis of hypertension or diabetes is not related to the current pregnancy
• Moderate or severe suicide risk (Level B2 or C measured by S-RAP)