Exposure to low levels of air pollution is linked to depression and anxiety, a new study suggests.

Research published yesterday (1 February 2023) has discovered that long-term exposure to low levels of multiple air pollutants is likely linked to experience of depression and anxiety.

In a study involving nearly 400,000 participants, the rate of depression and anxiety rose with the level of long-term exposure to multiple air pollutants.

While there may be many other factors at play, Dr Jing Huang at the Peking University School of Public Health in Beijing and their colleagues’ research shows there is an association between long-term exposure to air pollution and depression or anxiety.

Air pollution is increasingly recognised as an important environmental risk factor for our mental health and has been for other researchers too.

MQ Fellow Dr Helen Fisher, has been thinking along the same lines as these researchers. In a previous study which took 25 years to curate and was reported last year, Dr Fisher looked into the impact pollution has on the development of mental illnesses like depression, particularly how air pollution exposure for young people impacted their mental health. That study demonstrated that children growing up in bigger cities face a greater risk of mental illness due to higher levels of traffic.

Regarding that earlier study, Dr Fisher said:

“While we might like to think of our towns and cities as green and open spaces, it’s clear that there is a hidden danger that many will not have even considered.”

Dr Fisher was also involved in research around how childhood trauma can lead to psychosis later in life. Helen was also one of the lead researchers on MQ’s IDEA project which uses data from around the world to find the factors that put certain people at higher risk of developing clinical depression. The IDEA project would create a global tool to screen people for depression.

In Dr Huang’s recent study, researchers investigated the link between incidents of depression and anxiety and the pollutants in the air around the residential addresses of those taking part. While 389, 185 people gave their, some of them had not been diagnosed with depression or anxiety, and others had. Pollutants estimated for the areas the participants lived in included nitrogen dioxide and nitric oxide.

Participants had been recruited a while ago, most of them between the years 2006 to 2010. The findings were analysed last year and were published this week.

While the findings are interesting, further research into causality may be required to understand more comprehensibly the direct links and indirect factors that might contribute to these findings.

As ever, more research means better understanding. And that is why MQ strives to support mental health research in every way possible.