Mental Health Issues Alleviation in Sub-Sahara Africa: The role of Hairdressers

Last registered on September 24, 2025

Pre-Trial

Trial Information

General Information

Title
Mental Health Issues Alleviation in Sub-Sahara Africa: The role of Hairdressers
RCT ID
AEARCTR-0016805
Initial registration date
September 17, 2025

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
September 19, 2025, 10:16 AM EDT

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

Last updated
September 24, 2025, 2:14 PM EDT

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

Locations

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Primary Investigator

Affiliation
Santa Clara University

Other Primary Investigator(s)

PI Affiliation
Universite Paris Saclay

Additional Trial Information

Status
In development
Start date
2025-08-17
End date
2027-09-30
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Mental health care access remains limited in low- and middle-income contexts, prompting innovation in task-shifting interventions that leverage existing social networks. This randomized controlled trial (RCT) evaluates the Heal by Hair program in Lomé, Togo (2024), which trains hairdressers, trusted community actors, to deliver mental health promotion and basic support. The intervention comprises two arms: (1) a core training (3-day workshop + follow-up sessions) T1, and (2) an augmented "Heal by Hair Cercles" component, wherein trained hairdressers provide structured peer support to clients exhibiting severe symptoms (T2). Using a cluster-randomized design, we assign 800 hairdressers and 4,000 of their clients to either treatment (T1 or T2) or control groups. Primary outcomes include mental health knowledge (hairdressers), self-reported symptoms (hairdressers/clients), as well as a range of validated psychometric instruments (e.g., PHQ-9, GAD-7) collected during 12- and 24-month follow-up surveys. To address potential reporting bias, a subsample (n = TBD) will undergo clinical validation via 30-minute psychological assessments conducted by trained psychologists. Secondary analyses will explore heterogeneous effects by baseline predictors of our main outcomes using Generalized Random Forest. By testing a scalable, salon-based model, this study advances evidence on (1) the efficacy of mental health interventions led by lay mental health providers and (2) the incremental benefits of structured peer support ("Cercles"). Findings will contribute to literature on task-shifting in global mental health and inform policies on integrating mental health services into informal community networks in low income countries.
External Link(s)

Registration Citation

Citation
Bouguen, Adrien and Bjorn Nilsson. 2025. "Mental Health Issues Alleviation in Sub-Sahara Africa: The role of Hairdressers." AEA RCT Registry. September 24. https://doi.org/10.1257/rct.16805-2.0
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
The Heal by Hair program in Lomé, Togo (2024) trains hairdressers, trusted community actors, to deliver mental health promotion and basic support. The intervention comprises two arms: (1) a core training (3-day workshop + follow-up sessions), and (2) an augmented "Heal by Hair Cercles" component, wherein trained hairdressers provide structured peer support to clients exhibiting severe symptoms.
Intervention Start Date
2025-10-19
Intervention End Date
2026-06-30

Primary Outcomes

Primary Outcomes (end points)
WHO5 (well being), GAD7 (anxiety) and PHQ-9 (depression) psychometric tests
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
MHLS test (mental health knowledge test) for hairdressers and clientes , hairdressers' economic activity, reported mental health issues (clients and hairdressers)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The intervention comprises two arms: (1) a core training (3-day workshop + follow-up sessions) T1, and (2) an augmented "Heal by Hair Cercles" component, wherein trained hairdressers provide structured peer support to clients exhibiting severe symptoms (T2). Using a cluster-randomized design, we assign 800 hairdressers and 4,000 of their clients to either treatment (T1 or T2) or control groups.
Experimental Design Details
Not available
Randomization Method
The randomization will follow a re-randomization procedure: a re-randomization algorithm will run to achieve balance over a number of pre-determined (see PAP) baseline variables, so called rerandomization variables. A rerandomization variable is deemed balanced if having no significant differences between groups at the 10% significance level. The procedure will generate 1,000 random draws. The median one, number 501, will be chosen as our final random draw. If convergence issues arise (i.e. achieving 1000 draws is too slow or impossible), variables will be iteratively removed to reach 1000 randomizations in a reasonable time (typically below 8 hours).
Randomization Unit
salon/hairdresser
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
800
Sample size: planned number of observations
4000
Sample size (or number of clusters) by treatment arms
400/400 T/C the 200/200 T1/T2
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
At the client level, we estimate a minimum detectable effect (MDE) of 0.116 standard deviations (SD) for standardized impacts on mental health outcomes. At the hairdresser level, the MDE is 0.177 SD. These calculations account for covariate adjustment (assuming a baseline model R² of 20%), anticipated attrition (20%), and Intraclass correlation (ICC) of 20% (reflecting clustering of clients within hairdressers). These estimates do not incorporate the variance reduction expected from our re-randomization procedure, which iteratively minimizes covariate imbalance between treatment and control groups. Thus, the reported MDEs are deemed conservative.
IRB

Institutional Review Boards (IRBs)

IRB Name
Paris School of Economics/J-PAL
IRB Approval Date
2025-08-21
IRB Approval Number
2024-061
Analysis Plan

Analysis Plan Documents

PAP

MD5: b5aaedb76e94a6a92b45412d6961b2b2

SHA1: 40019c38023b71ab4e30258e14be3cba7d39fba1

Uploaded At: September 24, 2025