Healing by hair: local service providers as mental health first responders

Last registered on August 24, 2023


Trial Information

General Information

Healing by hair: local service providers as mental health first responders
Initial registration date
August 29, 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 29, 2022, 2:11 PM EDT

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

Last updated
August 24, 2023, 11:31 AM EDT

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


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Primary Investigator

Université Paris-Saclay

Other Primary Investigator(s)

PI Affiliation
the World Bank

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Mental health issues have large economic effects, yet care for such illnesses is severely underfunded in the developing world. This pre-analysis plan details the layout of a program to train hair dressers in Abidjan to act as first responders to women manifesting mental health issues. 150 hair dressers will undergo a three-day training event in November, 2022, run by African medical professionals. Each hair dresser, along with another 150 hair dressers who applied to the event but were not selected, will be interviewed along with five regular clients on three separate occasions, before and after the training. Field interviews will seek to collect information on both first stage (access and use of trained listeners) and second stage (well-being and depression scores) primary outcomes, as well as secondary outcomes (labor, gender norms).
External Link(s)

Registration Citation

Nilsson, Björn and Clémence Pougué Biyong. 2023. "Healing by hair: local service providers as mental health first responders ." AEA RCT Registry. August 24. https://doi.org/10.1257/rct.9989-1.1
Sponsors & Partners

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Experimental Details


Training of hair dressers in active listening and first response to mental health issues; the three-day training will be carried out by qualified African MDs specialized in psychiatry, according to guidelines from the WHO's mhGAP project. A random sample of regular clients of treated and control hair dressers will be surveyed at three points in time, before and after the intervention.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Depression score, well-being, indicator of perceived support.
Primary Outcomes (explanation)
Depression score will be based on the PHQ-9; well-being will be quanitified using the WHO-5 (1999) indicator of well-being, and perceived social support will be quantified using the MSPSS (Multidimensional Scale of Perceived Social Support).

Secondary Outcomes

Secondary Outcomes (end points)
A series of variables pertaining to employment and gender norms will be examined as secondary outcomes.
Secondary Outcomes (explanation)
Employment effects will be measured at the extensive and intensive margins (employed, and weekly workload), and earnings will be used as a proxy for productivity for the subsample of self-employed women. Gender norms will be measured using information on who in the household has a say about the use of interviewees' earnings, and a question of when (if) interviewees find it legitimate for husbands to beat their wives.

Experimental Design

Experimental Design
300 interested hair dressers will be pre-selected for training, and half of them will actually receive training (randomization will determine who). All hair dressers, along with five of their regular clients, will be interviewed before, shortly after and a year after the training. The design is thus a clustered randomized controlled trial.
Experimental Design Details
Not available
Randomization Method
Randomization done in an office by a computer.
Randomization Unit
Individual hair dressers.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
150 treated hair dressers, and 150 control hair dressers.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number