New research has demonstrated that air pollution doesn't just affect the climate, but it can also have an influence on our brains. The combination of exposure to high-PM air pollution and genetic susceptibility can substantially increase the risk of encountering depression for healthy people.

For the first time ever a study has demonstrated that genetic predisposition for depression in healthy people can be amplified by exposure to air pollution - *(Image Credit: YAKOBCHUK VIACHESLAV via Shutterstock / HDR tune by Universal-Sci)*

Risk of depression may be just a tiny fraction of the possible effects air pollution has on our brain as the brain circuits associated with the impacts of genetic risk and air pollution regulate a wide variety of critical cognitive, emotional, and problem-solving functions.

Genetic susceptibility for depression and air pollution amplify each other

Everybody has at least some inclination to potentially develop depression. Notwithstanding, some people are more prone to it than others due to a genetic predisposition.

Having a predisposition, however, does not mean that you will actually develop depression; it just increases the risk of developing it. The Lieber Institute research team has shown that the likelihood of developing depression is much higher when someone has a genetic predisposition and also lives in an area with a lot of air pollution, particularly in case of high-particulate-matter air pollution.

Particulate Matter (or PM) is a mixture of liquid droplets and solid particles found in the air. Dust, grime, soot, and smoke are examples of big particles that may be seen by eye. Others are so minuscule that only an electron microscope can detect them. These particles can be inhaled may cause serious health problems when they get deep into your lungs. (Some particles can even get into your bloodstream).

Particulat matter is one of the two main components of smog - *(Image Credit: Venturelli Luca via Shutterstock / HDR tune by Universal-Sci)*

This study has (for the first time ever) revealed that air pollution can alter the expression of genes that drive depression. Research lead Hao Yang Tan, explains that particular genetic predispositions for depression and air pollution can amplify each other. According to him, his phenomenon will lead to more people suffering from depression in highly polluted regions.

The study

The scientists enlisted over 350 healthy adults from Beijing for their research. The reason why Bejing was chosen had to do with the well-documented pollution levels in this city.

The research team used genotyping to compute each person's depression risk score, which is the statistical chance that a person would suffer from depression based only on genes.

Following that, the researchers gathered extensive information on each participant's relative exposure to air pollution during the previous six months.

Subsequently, the study participants had to partake in a series of easy brain tests while receiving an fMRI scan at the same time. The fMRI scan displayed what parts of the brain were activated during the tests.

Throughout the uncomplicated cognitive tests, participants were exposed to social stress in the form of unanticipated criticism about how they were performing. This had an impact on how an extensive network of brain circuits functioned during the tests.

Afterward, the scientists demonstrated that the combination of depression genes and the relative exposure to air pollution exposure damaged the aforementioned brain network disproportionately.

Protecting vulnerable people and reducing air pollution

This new knowledge should get governments to seriously reconsider their points of view about air pollution. According to the researchers, the effect of air pollution on the brain is no longer speculation.

There is a pressing need for scientists and policymakers to create strategies to detect and protect people that are vulnerable. In general, reducing air pollution should lead to enhanced brain function and a reduced risk of depression for citizens on a wide scale.

The team has published their paper in the peer-reviewed scientific journal: Proceedings of the National Academy of Sciences (PNAS) and is listed below.

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