Long-term exposure to air pollutants associated with geriatric depression

Long-term ambient exposure to air pollutants may increase the risk of depression in older adults, according to a study published in JAMA Network Open.

In a population-based longitudinal cohort study of U.S. Medicare enrollees aged older than 64 years, Xinye Qiu, PhD, a postdoctoral research fellow at Harvard University, and colleagues assessed long-term exposure to fine particulate matter (PM_2.5), nitrogen dioxide (NO₂) and ozone (O₃). Using data from the CMS Chronic Conditions Warehouse, Qiu and colleagues found that among 8,907,422 participants covered over a study period of 2005 to 2016, 1,526,690 were diagnosed with late-onset depression.

“These findings were robust to single, bi-pollutant or tri-pollutant model settings, as well as restricted to areas where the air pollution levels were always below current long-term regulation standards over the study period,” the researchers wrote.

The researchers reported that each five-unit increase in long-term mean exposure to each of the pollutants was associated with an increase in depression risk. Increased exposure to PM_2.5 was associated with a 0.91% (95% CI, 0.02-1.81) increase in depression risk, NO₂ was associated with a 0.61% (95% CI, 0.31-0.92) increase in risk and O₃ was associated with a 2.13% (95% CI, 1.63-2.64) increase.

“The study findings have implications for both environmental regulation and public health management,” Qiu and colleagues wrote. “We hope this study can inspire researchers to further consider possible environmental risk factors (such as air pollution and living environment) for the prevention of geriatric depression, to understand the disease better moving forward and to improve the delivery of mental health care services among older adults.”