Beside
Beside

The evidence

The evidence

We chose the Step-by-Step programme because the evidence behind it is unusually strong for a low-cost mental health intervention. Here is an honest summary of what the research shows — and what it does not yet tell us.

What the trials show

Step-by-Step has been tested in five randomised controlled trials in low- and middle-income countries, including Lebanon, China, and Egypt. Participants were adults with moderate to severe depression, assessed using the PHQ-9 depression scale.

In every trial, people who completed Step-by-Step showed significantly lower depression scores at three months compared with those in the control group. The effects were consistent across different countries and delivery contexts.

These are the kind of results you rarely see replicated this reliably across diverse settings. That consistency matters.

Cost-effectiveness

An independent analysis by Ambitious Impact (2025) estimated the cost of Step-by-Step at approximately $97 per DALY averted — that is, per year of healthy life restored. By comparison, many standard mental health interventions in high-income countries cost thousands of dollars per DALY.

This estimate is based on existing trial data and may shift as we gather real-world delivery costs. We will update it as our evidence base grows.

Read the full Ambitious Impact research report

What we do not yet know

The trials are strong, but they have limits. Here is what the current evidence cannot answer:

  • Effects beyond three months. All trials measured outcomes at three months. We do not yet have robust data on whether improvements are sustained at six or twelve months.
  • Completion rates at scale. Trial completion rates may not reflect what happens when a programme is delivered to thousands of people across diverse communities.
  • WhatsApp-specific delivery. The original trials used a mix of delivery formats. Beside delivers entirely via WhatsApp, which may affect engagement and outcomes in ways we have not yet measured.

We are committed to tracking and publishing our own outcomes data as the programme grows. We will not overstate what we know.

The research base

The five RCTs were conducted in:

  • Lebanon (conflict-affected Syrian refugees)
  • China (rural adults in low-resource settings)
  • Egypt (adults in primary care settings)

The programme was developed by the World Health Organization Department of Mental Health and Substance Use, in collaboration with local partners in each country.

For the independent cost-effectiveness analysis and programme overview, see the Ambitious Impact (AIM) research report: charityentrepreneurship.com