THURSDAY, July 14 (Health.com) — When most people think of suicide, they think of psychological problems such as depression and anxiety. But new research suggests that lung trouble may also play a role.
Two new studies conducted in Asia and published in the American Journal of Psychiatry report that asthma—and even days of unusually bad air pollution—appear to increase the risk of suicide.
As improbable as the link may sound, researchers suggest that respiratory problems may worsen a person’s mental state.
In the air pollution study—the first to examine a possible connection with suicide—researchers in South Korea tracked air quality and suicides in seven cities during 2004.
More than 4,300 suicides were reported that year. Just under half of those who committed suicide had at least one chronic health condition, such as heart disease, diabetes, cancer, chronic obstructive pulmonary disease (COPD), or mental illness.
When particulate matter (a common form of air pollution) spiked, the risk of suicide increased by 9% over the next two days, the researchers found. Among people with heart disease, the increased risk was even greater, about 19%.
John Mann, MD, a psychiatrist and professor of translational neuroscience at Columbia University, in New York City, says that while the study highlights an interesting statistical association, it does not prove a direct link between air pollution and suicides—or explain what might cause such a link.
The study offers an “intriguing and puzzling finding that clearly needs to be explored in more detail,” he says.
Although the authors of the study can’t say for sure what explains the link, they do have a few guesses. Substances in particulate matter—such as lead, mercury, or diesel exhaust—may somehow impact neurological functioning, they suggest. Or, particulate matter may cause inflammation, which is associated with cognitive problems and depression.
Inflammation is a factor in a wide range of other health conditions, including heart disease, and according to the researchers a third explanation may be that poor air quality worsens the symptoms of chronic illness, leading to psychological distress.
Next page: Suicide-asthma link seen
