Exposure to air pollution, especially early in life, is predictive of mental illnesses in the U.S. and Denmark

• New research found a link between poor air quality and higher rates of bipolar disorder as well as major depression in the U.S. and Denmark. 
• Additionally, it found a link between exposure to poor air quality in the first 10 years of life and a two-fold increase in schizophrenia and personality disorders in Denmark.
• Researchers analyzed two data sets: a U.S. health insurance claims database that showed claims for 150 million people and a Denmark database with information on 1.4 million people born in Denmark who lived there for at least their first 10 years of life.
• Based on their findings, the researchers believe that living in air polluted areas (specifically early in life) is predictive of mental illnesses in the U.S. and in Denmark.
• However, experts warn these associations do not necessarily mean causation and say there is a need for further research.

Quick Summary

Past research has focused on the effects of air pollution on mental health and found negative associations. A new study “Environmental pollution is associated with increased risk of psychiatric disorders in the US and Denmark” adds to these findings as it found that poor air quality was associated with higher rates of bipolar disorder and major depression in the US and Denmark. Additionally, exposure to air pollution in the first 10 years of life was linked to a two-fold increase in schizophrenia and personality disorders in Denmark. 

Goals

Experts know that many factors come into play in the development of a mental illness. But the researchers in this study focused on the potential environmental factors. They hypothesized that air pollutants might affect neuroinflammatory pathways in the brain that have been shown to cause depression symptoms in animals.

Investigation

To investigate, the research team analyzed two data sets, one from the U.S. and another from Denmark: the first was a U.S. health insurance claims database that showed 11 years of claims for over 150 million people, and the second was a database with information on 1.4 million individuals born in Denmark between 1979 and 2002 who lived there at least until their 10th birthday.  

The researchers used the US Environmental Protection Agency’s air quality measurements for the U.S. group and a national pollution register for the individuals in Denmark to estimate air pollution exposure during the first 10 years of life. 

Results

The team found a link between poor air quality and higher rates of bipolar disorder and major depression in both populations. Interestingly, though, in Denmark, air pollution exposure in the first 10 years of life was also linked to a two-fold increase in schizophrenia and personality disorders. 

The researchers concluded that living in air polluted areas (specifically early in life) is predictive of mental illnesses in the U.S. and in Denmark. They say that more research is needed to better understand the environmental factors that come into play in the development of psychiatric disorders.

Limitations

• Researchers warn that the links found between poor air quality and mental illnesses do not necessarily mean causation.
• They add that more research is needed to better understand whether neuroinflammatory effects of poor air quality are similar to those of other stress-induced conditions. 

Sources:

Khan, A., Plana-Ripoll, O., et al (2019, August 20). Environmental pollution is associated with increased risk of psychiatric disorders in the US and Denmark. PLOS. Retrieved from https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000353

PLOS. (2019, August 20). Is pollution linked to psychiatric disorders?. ScienceDaily. Retrieved December 10, 2019 from www.sciencedaily.com/releases/2019/08/190820141604.htm

Start a Relationship with An Exceptional Counselor