Data from the largest mental health survey of the Flint, Michigan community indicate that an estimated one in five adults, or roughly 13,600 people, had clinical depression, and an estimated one in four, or 15,000 people, had PTSD five years after the water crisis began.

“The mental health burden of America’s largest public-works environmental disaster clearly continues for many adults in Flint,” says Aaron Reuben, a postdoctoral scholar at Duke University who led the research, which appears in JAMA Network Open.

On April 25th, 2014, the city of Flint switched its water supply from Lake Huron and the Detroit River to the Flint River and failed to properly treat the water supply to prevent lead and other elements from leaching out of the city’s old water pipes. Virtually all Flint residents were consequently exposed to drinking water with unsafe levels of bacteria, disinfection byproducts, and lead, a neurotoxicant.

Flint drinking water was not declared lead-free until January 24, 2017. During the crisis, tens of thousands of children and adults in Flint developed high blood-lead levels, putting them at greater risk for cognitive deficits, mental health problems, and other health problems later in life.

“We know that large-scale natural or human-caused disasters can trigger or exacerbate depression and PTSD,” says Dean Kilpatrick, professor in the psychiatry and behavioral sciences department at Medical University of South Carolina and senior author of the study.

Kilpatrick notes that there was clear evidence of high rates of mental health problems in the Flint community during the first years of the crisis. “What we did not know until now was the extent to which Flint residents continued to have mental health problems at the clinical diagnosis level five years after the crisis began.”

Past year rates of depression and PTSD identified in Flint today are three to five times greater than national estimates among US adults overall, Kilpatrick says, and likely result from a combination of higher base rates of mental health problems in Flint before the crisis as well as a significant exacerbation of problems resulting from the crisis.

Read the full article about the mental health burden of the Flint water crisis at Futurity.