The floods may last for days or weeks. But for many people living in Kenya’s vulnerable communities, the emotional scars can linger for months, years, or even a lifetime.
When heavy rains pound rooftops in flood-prone settlements, many residents do not merely worry about rising water levels. They worry about losing their homes, their possessions, their livelihoods, and sometimes their loved ones. For some, the sound of thunder alone is enough to trigger fear, panic, and memories of past disasters.
While climate change is often discussed through images of submerged homes, washed-away roads, failed harvests, and displacement, researchers are now drawing attention to a less visible consequence of extreme weather events: their impact on mental health.
A groundbreaking multi-country study conducted by the African Population and Health Research Centre (APHRC) is revealing how repeated exposure to flooding is contributing to depression, anxiety, and post-traumatic stress disorder (PTSD) among vulnerable populations living in informal settlements.
The findings, shared with residents and policymakers in Kisumu’s Manyatta settlement under the Weather Events and Mental Health Analysis (WEMA) Project, paint a worrying picture of a growing mental health burden linked to climate-related disasters.
The WEMA project is being implemented in Kenya, South Africa, Mozambique, and Burkina Faso. In Kenya, researchers focused specifically on flooding, one of the country’s most destructive climate hazards.
“We are trying to understand how extreme weather events affect mental health among vulnerable populations,” explains Moustapha Tall, a researcher at APHRC.
“The project is implemented across four African countries. In Kenya, we focused on floods because they represent one of the biggest climate hazards affecting vulnerable communities,” Dr Tall said.
For the past two years, researchers have been collecting data from two urban informal settlements: Mukuru kwa Reuben in Nairobi and Manyatta in Kisumu. The goal was to understand how exposure to flooding influences mental well-being.
Researchers selected Mukuru kwa Reuben because of its frequent flooding, while the section of Manyatta included in the study experiences comparatively less flooding and served as a control site.
The comparison allowed researchers to isolate the mental health effects associated with flood exposure. The findings were striking.
According to Henry Odero, a Monitoring, Evaluation and Research officer at APHRC, one mental health condition stood out more than any other: PTSD. The study found that PTSD’s prevalence was significantly higher among residents exposed to flooding.
In Mukuru kwa Reuben, 44 per cent of residents screened were positive for PTSD compared to 30 per cent in Manyatta. Researchers say the findings demonstrate a strong association between flooding and trauma-related mental health conditions.
“Our evidence really shows that PTSD is highly associated with flooding,” says Odero.
“When we listened to community members and analysed their stories, we realised flooding is not simply about losing property or household items. The fear remains long after the floods are gone.”
Residents described living with constant anxiety whenever dark clouds gather or heavy rain begins to fall.
For many, memories of previous flooding events remain deeply embedded in their minds.
“The anxiety that comes whenever people hear thunder or think that it is going to rain again is one of the things contributing to PTSD,” Odero explains.
Researchers found that repeated exposure to flooding creates a cycle of fear and anticipation that can become psychologically exhausting.
Unlike physical losses that can eventually be replaced, emotional trauma often remains hidden and untreated.
The study examined three common mental health disorders: depression, anxiety, and PTSD. While anxiety levels were relatively similar across both communities at around 15 per cent, depression was somewhat higher in Mukuru kwa Reuben.
Approximately 24 per cent of residents in Mukuru kwa Reuben screened positive for depression compared to 19 per cent in Manyatta.
Although researchers noted that this difference was not statistically significant, the trend still pointed toward a heavier burden among flood-exposed populations.
When all common mental health disorders were combined, the picture became even more alarming. More than half of residents in flood-prone Mukuru kwa Reuben, 51 per cent, screened positive for at least one mental health condition. In Manyatta, the figure stood at 37 per cent.
The findings suggest that while mental health challenges are already widespread in informal settlements due to poverty, unemployment, overcrowding, insecurity, and limited access to services, climate-related flooding significantly worsens the situation.
“What this tells us is that there is already a high burden of mental health disorders in informal settlements,” says Odero, warning:
“But there is a margin that can clearly be associated with climate change and flooding.”
