Digital delivery of Behavioural Activation to overcome depression and facilitate social and economic transitions of adolescents in LMICs (DoBAT)

Last registered on January 18, 2023


Trial Information

General Information

Digital delivery of Behavioural Activation to overcome depression and facilitate social and economic transitions of adolescents in LMICs (DoBAT)
Initial registration date
August 23, 2022

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
August 25, 2022, 2:27 PM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Last updated
January 18, 2023, 6:44 AM EST

Last updated is the most recent time when changes to the trial's registration were published.


Primary Investigator

University of the Witwatersrand

Other Primary Investigator(s)

PI Affiliation
University of Oxford
PI Affiliation
University of California Los Angeles
PI Affiliation
University of Cambridge
PI Affiliation
Exeter University
PI Affiliation
University of the Witwatersrand
PI Affiliation
University of the Witwatersrand
PI Affiliation
University of Cape Town/King’s College London
PI Affiliation
University of Limpopo
PI Affiliation
University of Oxford
PI Affiliation
University of Exeter
PI Affiliation
University College London
PI Affiliation
University of Oxford
PI Affiliation
University of the Witwatersrand
PI Affiliation
University of the Witwatersrand
PI Affiliation
University of the Witwatersrand

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
This study will use low-end smartphones to adapt and deliver a tailored psychological therapy, Behavioural Activation among adolescents (15 to 19 years old) with depression in rural South Africa. We will assess the feasibility, acceptability, and determine the preliminary efficacy of the intervention (primary objective). As a secondary objective, we will pilot a range of mental health, social-affective cognition, risky behaviours, and socioeconomic measures; and collect descriptive data on trial procedures to inform key parameters in the development of a further large-scale trial.
External Link(s)

Registration Citation

Blakemore, Sarah-Jayne et al. 2023. "Digital delivery of Behavioural Activation to overcome depression and facilitate social and economic transitions of adolescents in LMICs (DoBAT)." AEA RCT Registry. January 18.
Experimental Details


The DoBAt study will be an individual randomised control trial in which participants are randomly allocated to each of the intervention and control arms. All participants in the intervention and control arms will be given a low-end smartphone (which they can keep at the end of the study).

Participants in the intervention arm will receive Behavioural Activation therapy delivered via a smartphone app implemented over 10 weeks. The app consists of six tailored modules that contain Behavioural Activation’s core principles integrated into a gamified format. The app will be supplemented by brief phone calls (15 mins per module) from Trained Peer Mentors.

Participants in the control group will get access to an app that contains short video clips from WildEarth-SafariLive, a locally produced wildlife documentary series.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
(1) Feasibility and acceptability of the intervention
(2) Initial efficacy (direction and magnitude) of any effects of the intervention on depressive symptoms
Primary Outcomes (explanation)
(1) Feasibility and acceptability of the intervention. A mixed-methods approach will be adopted to establish feasibility and acceptability.
Feasibility will be assessed by collecting data on the following:
• Recruitment (enrolment rate of eligible participants) and retention in the trial at the end of the intervention period (11 weeks).
• Feasibility of testing procedures and data collection methods, including assessment of completion rates.
• Treatment adherence rates, where adherence is defined as having opened at least 4 out of 6 of the app modules and as having completed 3 out of 6 phone calls with the peer mentor (excluding the introductory call). We will complement the treatment adherence rates with engagement metrics collected via the app (number of times participants logged into the app, number of modules opened and completed, total time spent on the app, number of weekly activities set to do, and number of times the participant completed the weekly activities).

Acceptability of the intervention and study procedures will be assessed via:
• An acceptability questionnaire conducted at the end of intervention assessment (week 11) with all participants. The questionnaire consists of three measures: Acceptability of Intervention Measure (AIM), Intervention Appropriateness Measure (IAM), and Feasibility of Intervention Measure (FIM). Each measure consists of 4 items. The total score ranges from 1 to 5 and is calculated by averaging response scores to the response categories. We will calculate an average score for each of the measures. We will inquire about the acceptability of the app using these three measures (to both the intervention and control groups) and the acceptability of the peer mentor programme (to the intervention group only).
• In-depth interviews with a subsample of participants. We estimate that interviews with 20 participants will provide a sufficient range of experiences and perspectives to reach data saturation. This subsample will contain participants from the treatment and control arms and will be stratified based on high versus low app engagement.

Fidelity of delivery of the intervention will be assessed by collecting data on adherence and competence of Trained Peer Mentors.
• Adherence of the peer mentors is defined as the number of sessions that meet at least 90% of the criteria for adherence according to the training protocol. Independent raters will listen to a random sample of recordings of Peer Mentors’ phone calls with participants and assess them against the training protocol.
• Competence of the peer mentors will be expressed as a percentage based on their Competency Assessment Test. This test will include a written test and observation of skills through role-playing to assess Knowledge, Attitudes and Practices. Tests will be scored by the Trial Psychologist using a pre-determined scoring system.

(2) The initial efficacy of the intervention will be assessed by looking at differences between treatment and control group in the scores of the 9-item Patient Health Questionnaire Adolescent version 9-item (PHQ-A) at the end of intervention assessment (week 11). Outcomes will be compared between intervention and control groups using a linear regression model and adjusting for covariates (PHQ score measured at baseline, sex, age, depression severity, and household asset index). As a secondary analysis, we will make use of the repeated measurements of the PHQ-A throughout the trial (up to 6 times per individual) to evaluate the treatment effects over time.

Secondary Outcomes

Secondary Outcomes (end points)
Pilot locally adapted outcome measures of mental health, cognition, risky behaviours, socioeconomic measures, and collect descriptive data to inform the development of a further larger trial.
Secondary Outcomes (explanation)
Mental health outcomes: General Anxiety Disorder (GAD-7), Conor-Davidson Resilience Scale (CD-RISC), Brief Rumination Response Scale (RRS), Emotional wellbeing (WEMWBS), Behavioural Activation for Depression Scale (BADS).

Cognition outcomes: emotion recognition, working memory, task switching, risk-taking, non-verbal reasoning

Risky behaviours: risky sexual behaviours, substance use, delinquency, gambling

Economic measures: time preference, risk preference, loss aversion. In addition, we will measure a range of socioeconomic outcomes, including measures of time use, human capital investment, and spending.

Experimental Design

Experimental Design
This pilot study is a two-arm single-blind individual-level randomised control trial. Enrolled participants will be individually randomised into intervention or control arms of the study (100 participants each).
Experimental Design Details
Randomization Method
Participants will be randomly assigned to the intervention or control arm with a 1:1 allocation using a computerised minimisation algorithm, balanced by sex (male or female) and severity of depressive symptoms (<10 or ≥ 10 on the PHQ-A). The minimisation algorithm was generated by the Centre for Healthcare Randomised Trials (CHaRT) at the University of Aberdeen.
Recruitment will be staggered over 6 months.
Randomization Unit
Individual level randomization
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
200 individuals.
Sample size: planned number of observations
200 individuals.
Sample size (or number of clusters) by treatment arms
100 individuals in treatment arm, 100 individuals in control arm.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Statistical power was calculated to detect differences between two independent groups, in a two-sided test with an α of 0.05 and a power of 1–β=0.80, for an effect size of 0.45. This effect size is based on findings from previous studies investigating digital psychological interventions, with effect size (Cohen’s d) ranging from 0.24 to 0.57. Given these findings, we chose a small-to-medium effect size of 0.45 to account for the limited number of studies conducted with our target population and in our study setting. We allowed for 25% attrition, based on a previous study with adolescents in the study setting. Given these assumptions, we aimed to recruit 200 participants at baseline. We calculated the required sample size using G*Power software, version

Institutional Review Boards (IRBs)

IRB Name
University of the Witwatersrand Human Research Ethics Committee
IRB Approval Date
IRB Approval Number
IRB Name
Oxford Tropical Research Ethics Committee (OxTREC)
IRB Approval Date
IRB Approval Number
OxTREC 34-20
IRB Name
Mpumalanga Provincial Department of Health Research Committee
IRB Approval Date
IRB Approval Number


Post Trial Information

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Reports & Other Materials