Pollution increases the risk of depression

Air pollution harms our mental health. This is the conclusion of a study published in JAMA Network Open, Friday, February 10. According to its authors, scientists from Harvard University, exposure to polluted air increases the risk of depression later in life. This is one of the first studies to focus on the link between depression and long-term exposure to pollution. “This is one of the main reasons why we wanted to conduct this analysis“, says Dr. Xinye Qiu, co-author of this new study, and postdoctoral researcher in the Department of Environmental Health at the Chan School of Public Health at Harvard, in an interview with CNN. “Surprisingly, we found a large number of late-onset depression diagnoses in this study.”

Pollution: what is the link with the risk of long-term depression?

This scientific work is based on the information of more than 8.9 million people over the age of 64 and registered in a US health insurance program. To determine the level of pollution exposure of study participants, Xinye Qiu and her co-authors observed where each of the people diagnosed with depression lived and created models to determine the average exposure to pollution by postal code and over a year. The researchers focused on three types of air pollution: fine particles, also known as PM2, nitrogen dioxide and ozone.

According to their findings, people who lived in areas with higher long-term pollution levels had an increased risk of being diagnosed with depression. All three pollutants studied were associated with a higher risk of late-onset depression, even at lower levels. “There is therefore no real threshold, this means that the policies of the future will have to eliminate this pollution or reduce it as much as possible because it carries a real risk.“, observes Xinye Qiu.

Pollution and depression: who are the people at risk?

Research has also shown that the risk of depression associated with air pollution is greater in socio-economically disadvantaged groups. According to the researchers, this is potentially linked to the fact that they are exposed to stress in addition to these poor environmental conditions. Older people who had heart or respiratory problems were also more susceptible to the risk of late-onset depression when exposed to nitrogen dioxide pollution.

Depression: what will be the consequences of global warming?

“Depression at the end of life is a geriatric problem that the public and researchers need to pay more attention to, as is the case with Alzheimer’s disease or other neurological conditions.“, estimates Xinye Qiu on the site of CNN. The scientist is concerned about the effects of climate change on mental health. Ozone pollution will rise as temperatures rise, and he finds that this pollutant is one of the pollutants most strongly associated with Late Depression.