Exposure to traffic-related air pollution is associated with increased mental health illness among people recently diagnosed with psychotic and mood disorders such as schizophrenia and depression according to new research by University of Bristol.
The research includes data from over 13,000 people and has been published in a recent issue of the British Journal of Psychiatry. It reveals that increased use of mental health services reflects mental illness severity, suggesting that initiatives to lessen air pollution could improve outcomes for those with these disorders and reduce costs of the healthcare needed to support them.
Previous research found that adults exposed to high levels of traffic-related air pollution are more likely to experience common mental health disorders such as anxiety and mild depression but, until now, little was known about whether air pollution exposure contributes to the course and severity after the onset of more serious mental illness.
Researchers analysed data from 13,887 people aged 15 years and over who had face-to-face contact with South London and Maudsley NHS Foundation Trust services between 2008 and 2012. Individuals were followed from the date of their first face-to-face contact for up to seven years.
The study found people exposed to higher residential levels of air pollutants used mental healthcare services more frequently in the months and years following their initial presentation to secondary mental healthcare services compared to those exposed to lower air pollution.
The researchers found that for every three micrograms per cubic meter increase in very small particulate matter and 15 micrograms per cubic meter increase in nitrogen dioxide over a one-year period there was an increased risk of having an inpatient stay of 11% and 18%.
Results also showed increases in nitrogen dioxide were associated with a 7% and 32% increased risk of requiring community-based mental healthcare for the same period. These findings were also replicated over a seven-year period.
King’s College of London senior lecturer in biostatistics and epidemiology and lead author of the study Dr Ioannis Bakolis said, “Our research indicates that air pollution is a major risk factor that is easily modifiable which suggests more public health initiatives to reduce exposure such as low emission zones could improve mental health outcomes as well as reduce the high healthcare costs caused by long-term chronic mental illness.”
Bristol Medical School research fellow and first author of the study Dr Joanne Newbury said, “These findings for both mood disorders and psychotic disorders, as well as for both inpatient and community-based mental healthcare and over seven years follow-up suggest that air pollution may contribute to a broad range of mental health problems, across a wide spectrum of clinical need and over long periods of time.” A