February 13, 2023 – Researchers at Harvard and Emory Universities have found a link between long-term exposure to air pollution and the diagnosis of depression after age 64.
“Depression in older people is a cause for concern and can be as serious as dementia,” the authors write, declaring that previous studies have shown the consequences of air pollution on mental health.
The study was published on Friday in JAMA network opened. Researchers analyzed Medicare data from 2005 to 2016 for 8.9 million people ages 64 and older, 57% of whom were female and 90% white. More than 1.5 million people were diagnosed with depression in the course of the study.
The researchers examined air pollution data for the zip code related to each study participant's place of residence over a 16-year period. The three air pollutants examined were:
- particulate matterThese are tiny particles that could make the air appear cloudy when there’s loads of pollution.
- ozonealso often called smog, which comes from sources similar to exhaust pipes and chimneys.
- Nitrogen dioxidewhich is considered one of the gases produced by the combustion of fossil fuels similar to coal, oil, gas or diesel.
Prolonged exposure to every of the three pollutants was related to an increased risk of recent depression. The researchers found that exposure to nitrogen dioxide was particularly dangerous.
Depression in later life is usually underdiagnosed, in accordance with the CDCbecause “medical professionals may mistakenly believe that symptoms of depression in older people are a natural response to illness or to the life changes that come with age, and therefore may not view depression as something that needs to be treated.”
“That’s one of the main reasons we wanted to conduct this analysis,” said Xinye Qiu, PhD, a researcher on the Harvard TH Chan School of Public Health CNN“Surprisingly, we found a large number of late-onset depression diagnoses in this study.”
The authors write that they hope that each environmental agencies and public health officials will consider the consequences of air pollution when stopping depression in older people.
“We hope that this study can inspire researchers to pay more attention to potential environmental risk factors (such as air pollution and living environment) in preventing depression in old age, to better understand the disease in the future, and to improve the provision of mental health services for the elderly,” they write.