Air pollution now linked to late-life depression
Just days after a study posited the negative effects of air pollution on unborn babies, new research in America suggests it is also a potential risk factor for late-onset depression in the over-65s.
The study involved a vast cohort of nearly 9m people who were enrolled on Medicare – America’s health insurance program for people age 65 or older – and covered a ten year period. Using Medicare records, it was possible to follow any changes of address the subjects made and predict their exposure to air pollutants by using high-performance air pollution prediction models. In this research, the pollutants being considered were PM2.5, nitrogen dioxide and ozone.
Through the Chronic Conditions Data Warehouse (a database designed to make data from organisations such as Medicare more readily available for research) the researchers could identify the date of the first occurrence of a depression diagnosis, of which there were 1,526,690. A five year washout period was implemented, to increase the chance that a participant was not an existing depression patient prior to the Medicare diagnosis.
The research found that each incremental increase in long-term mean air pollution exposure was associated with a statistically significant risk of depression, leading the report to conclude that there are: ‘significant harmful associations between long-term exposure to elevated levels of air pollution and increased risk of late-life depression diagnosis.’
These results were published only a month after we reported on research that suggested a link between air pollution and suicide.
Commenting on the report Prof Oliver Robinson, Professor of Neuroscience and Mental Health, University College London (UCL), said: ‘This adds to a growing picture that we should be concerned about the effects of pollution on mental health on top of the more obvious links to respiratory health.’
He went on put these results into a UK perspective: ‘This work has implications for places like London because the median NO2 exposure in this study is 15.4 but, for example, the Tower Hamlets area which is currently discussing pollution exposure policies, is currently double this at 33.7, which is at the most extreme end of this studies’ data and would mean there is a substantially greater exposure and risk in London.’
Image: Matt Bennett
