The purpose of the present study is to evaluate the changes on mental and physical health deriving from a blended intervention merging psychological intervention aimed at increasing activity and exercise with a personalised exercise program based on medical assessment on subjects suffering from mild to moderate depressive symptoms irrespective of diagnostic entity, by comparing two experimental groups (A. Personalised exercise group program+ app with motivational messages + fitness tracker or B. Personalised exercise group program+ app with no motivational messages + fitness tracker) and a control group (app with no motivational messages +fitness tracker). This study also introduces the use of a wearable device to collect information regarding physical activity and sleep patterns to provide motivational messages.

The investigators hypothesise that participation in a brief app-blended group intervention -on top of usual care- promoting personalised exercise and activity will improve functioning and well-being of participants, as well as motivate them to increase their physical activity and enhance behavioural changes towards a healthier lifestyle when compared to general exercise prescriptions. In addition, the investigators hypothesise that amongst patients who had been allocated to the intervention conditions, those presenting better commitment to prescribed personalised exercise plans (understood as more than a 70% compliance of prescribed exercise, measured by objective movement data collected by a fitness tracker) will show a higher functionality improvement.

OBJECTIVE

Primary:

·To evaluate the changes on functioning deriving from a blended intervention merging psychological intervention aimed at increasing activity and exercise with a personalised exercise program based on medical assessment on subjects suffering from mild to moderate depressive symptoms.

Secondary:

• To test the differential effect of the above-mentioned blended exercise program on wellbeing, depressive symptoms and physical activity performance of patients with depressive symptoms, by comparing the three study arms.
• To measure wellbeing of patients allocated to the personalised exercise program, compared to the group condition.
• To assess and compare antidepressive response within both groups and intra subject at interim visits and final assessment.
• To measure effects of a personalised exercise program on exercise capacity and strength.

Exploratory:

· To study gender differences concerning all treatment outcome parameters.

STUDY DESIGN The investigators will conduct a 3-arm randomized controlled clinical trial in which eligible participants will be allocated to one of the following conditions: a)Intervention A: Personalised exercise group program + fitness tracker + IDEApp with motivational messages; b)Intervention B: Personalised exercise group program + fitness tracker + IDEApp without motivational messages; c) Control Group: fitness tracker +IDEApp without motivational messages.

All participants, regardless of their treatment condition, will be read a short text about the the benefits of regular exercise on mood during the initial clinical interview, in order to make sure that they have listened to this unspecific advice at least once.

This study seeks to investigate the effects of personalised exercise on top of usual care. All participants will continue receiving naturalistic pharmacological and/or psychological treatment, without any research-related disruption.

TARGET POPULATION Male and female patients with current depressive symptoms regardless of diagnosis entity.

SETTING Outpatient mental health centres and General Practice(GP) surgeries belonging to the healthcare network of Hospital del Mar in Barcelona, Spain. Referrals will be made by any general practitioner, nurse, psychologist or psychiatrist treating the patient. Group sessions will be facilitated by a psychologist (Psychology BSc, MSc) and a physiotherapist (Physiotherapy BSc, MSc) who will undertake brief and intuitive therapy training.

Before any study procedures occur, participants will be informed about the study characteristics, will be provided with a study information leaflet and a written informed consent form must be signed by them. After signing the informed consent, a competent practitioner will confirm or disregard depressive symptomatology, administer the MADRS and judge that the subjects fulfil all the inclusion criteria items and none of the exclusion criteria requirements.

INTERVENTION The main goal of the intervention is to personalise exercise prescription and enhance motivation towards being physically active. To fulfil our objectives, a collaborative team of psychologists, Physical Medicine and Rehabilitation specialists, and one psychiatrist developed a brief group intervention -the IDEA programme- and an ad-hoc made app to register and store the participants' physical activity, exercise compliance and sleep patterns.

In the exercise-oriented sessions, participants will be asked to wear sports clothes to practice the individualised exercise prescription on-site and will receive an individual brochure with indications and photographs of their prescription.

For the implementation of the sessions, the research team developed a guide for the professionals with the content of each session and its dynamics. In the case of the individualised exercise prescription, a pool of exercises was created in order to standardize the potential exercises that will be chosen individually for each participant.

MOBILE APPLICATION DEVELOPMENT A collaborative team of psychologists, Physical Medicine and Rehabilitation specialists and software engineers developed a user-friendly smartphone application (IDEApp) that can be synchronised to a fitness tracker. The fitness tracker will register and store data regarding physical activity and sleep patterns. IDEApp will collect two types of data: objective and self-informed. Objective data will include the number of daily steps, aerobic exercise -including minutes, distance in metres, maximum, minimum and average heart rate- and sleep structure -including duration in a 24-hour period, deep and light sleep discrimination-. Self-reported data will require participants to simply indicate on IDEApp whether one of three exercise options have been performed: 1) relaxation, 2) stretching, or 3) strength and endurance.

When non-compliance with the exercise prescription, physical activity decreases, or altered sleep patterns are detected, the system will trigger motivational or awareness messages through the app.

NUMBER OF SUBJECTS 172 participants with mild to moderate depressive symptoms irrespective of diagnosis entity will complete the study.

RECRUITMENT The recruitment period will extend over 12 months and all participants will be given away an activity band that will be free to use together with free access to the app after study completion.

IMPLEMENTATION Allocation and intervention assignment will be automatically generated by the IDEApp web-based platform once participants are registered in the system by study staff. Participants will be enrolled in the trial by a study psychologist after baseline assessment.

ASSESSMENT Participants will attend the study entry clinical interview and baseline assessment, followed by an evaluation with a physiotherapist to identify their physical needs and capabilities. Such assessments will allow the subsequent prescription of tailored exercise to the intervention groups. After baseline assessment, the study staff will install IDEApp on the smartphone of all participants and provide them with the activity band. In the first week after study entry, all subjects will effectively start using the devices and IDEApp, which will provide estimates of their baseline physical activity and exercise, and up until the end of the trial.

After group sessions completion (after 1 month for Control Group), every participant will be followed by an eight-month follow-up. Post-allocation assessments following the intervention at 4-weeks (T1) and 12-weeks (T2) will be carried out by telephone. The final assessment at 36-weeks (T3) will be carried out face-to-face and will follow a similar outline as the baseline assessment.

DATA MANAGEMENT Study data will be collected, entered and managed using REDCap electronic data capture tools hosted at Hospital del Mar Medical Research Institute (IMIM). More specifically, data will be collected offline in the REDCap mobile app on an Android tablet and then will be sync back to the project on the REDCap server. A password system will be utilized to control access to data and the activity that researchers may undertake is regulated by the privileges associated with their user identification code.

STATISTICAL ANALYSIS PLAN FOR PRIMARY AND SECONDARY OUTCOMES Statistical analysis will be performed using the software SPSS Statistics 25. Descriptive statistics will be used to analyse the distribution of socio-demographic and clinical characteristics among groups at baseline. Continuous variables with a normal distribution will be analysed performing an ANOVA. Where the premises of normalcy are not met, the Wilcoxon test will be used. The differences between groups on the categorical and mail clinical variables will be evaluated by using a Chi-square test. Those variables that are statistically significant may be used as covariates for a logistic or linear regression study of the factors associated with the magnitude of the effect, and determine which variables are better predictors of functioning. The effect size index will be estimated in case of correlation indexes for each of the performed analyses. To analyse efficacy the investigators will perform intention to treat analysis. Analysis will be two-tailed and the significance set a p <0.05.

Last Observation Carried Forward analysis will be used to handle and minimize missing data on the clinical variables.

ENDPOINTS

Primary endpoint

●Change in psychosocial and occupational functioning of subjects allocated to both the experimental conditions (A+B) versus control condition, as measured by the SF-36 from baseline to week 36 and from baseline to interim visits.

Secondary endpoints

• Improvement in wellbeing of subjects allocated to both the experimental conditions (A+B), as measured by the WHO-5 Well-Being Index (WHO 5 WBI) from baseline to week 36 and from baseline to interim visits.
• Improvement in depressive symptoms of subjects allocated to both the experimental conditions (A+B), as measured by the Patient Health Questionnaire (PHQ-9) from baseline to week 36 and from baseline to interim visits.
• Improvement in current physical activity of subjects allocated to both the experimental conditions (A+B), as measured by the Simple Physical Activity Questionnaire (SIMPAQ) from baseline to week 36 and from baseline to interim visits.
• Change in functional exercise capacity using the 6-minutes walking test (6MWT) from baseline to week 36 in subjects receiving experimental conditions (A+B) of personalised exercise prescription versus control condition. The change in the distance walked in the 6MWT after completion of the program will be used to evaluate the effectiveness of the personalised exercise program. For the evaluation of dyspnea and subjective fatigue, the short Borg CR 10 Scale will be used before and after the test.
• Change in functional exercise capacity using the 1-min STS test from baseline to week 36 in subjects receiving experimental conditions (A+B) of personalised exercise prescription versus control condition.
• Change in isometric muscle strength of the hand and the forearm using the handgrip strength test from baseline to week 36 in subjects receiving experimental conditions (A+B)of personalised exercise prescription versus control condition. The equipment used will be a Jamar Plus+ digital hand dynamometer, grip strength will be measured 3 times per hand in the 2-handle position.
• Proportion of participants allocated to the experimental conditions (A+B) presenting better commitment to prescribed personalised exercise plans -understood as more than a 70% compliance of prescribed exercise-measured by objective activity data recorded by the smartband-at follow-up visits.
• Change in physical activity and enhancement of a healthier lifestyle-as measured by activity and sleep objective data provided by a smartband and an ad-hoc-designed app- from baseline to week 36.

Inclusion Criteria:

• Aged >18-<65 years
• Presenting mild to moderate depressive symptoms according to Montgomery-Asberg Depression Rating Scale (MADRS score>16 & <34)
• Currently owning an Android compatible smartphone
• Fluent in the Spanish language
• Basic knowledge and skills using information and communication technology
• Be able to provide written informed consent to participate

Exclusion Criteria:

• Severe cognitive and/or physical impairment
• Cognitive deficit or developmental disorder
• Current psychotic, melancholic, or catatonic features
• Drug or alcohol abuse
• Modification of drug treatment (or its dose) in the last month (or plan for it
• Beginning of psychological treatment in the last month
• Beginning of biophysical treatment in the last month
• BMI >40
• Physical disability.

After assignment to study conditions, participants and investigators will be blinded to one aspect of the specific experimental intervention (receiving or not motivational messages). Both will know whether participants have been allocated to experimental or control conditions but the specific experimental intervention (A or B) will not be revealed. To avoid assessment bias, an independent evaluator blinded to group allocation will complete follow-up assessments.

Clinicians, principal investigators, and statisticians will be also blinded to the randomization procedure and group allocation.