According to the first-ever study of its kind, teenagers who live near polluted roads are about 40 percent more likely to be psychotic. The researchers say that air pollution has helped explain that youngsters in heavily polluted urban areas are twice as likely to suffer from psychosis than those living in rural areas.
Whilst the research does not conclusively prove that psychosis is caused by traffic fumes, it supports data that says that pollution causes far-reaching damage to the brain and lungs.
It has been long known that fine particles and nitrous oxides in the air lead to breathing and heart problems but now, evidence suggests that they also contribute to depression and dementia.
2,232 teenagers in England and Wales were surveyed about psychotic experiences, including whether they heard voices or felt they were being watched, the responses were used by researchers for this study.
Almost a third of the respondents stated that they had had such experiences and while most will grow out of these experiences, they are still at a higher risk of experiencing full-blown psychosis.
The responses were then compared with detailed empirical modeling of pollution levels at the teenagers’ homes. It was found that psychotic experiences were considerably more regular among teenagers exposed to higher levels of air pollution, said Joanne Newbury, of King’s College London, lead author of the paper.
For example, teenagers exposed to the highest levels of nitrous oxides had 72 per cent greater odds for psychotic experiences compared with those with lower exposure.
In the areas with the highest nitrous dioxide levels, almost 38 percent of youngsters admitted to psychotic experiences as compared to 27 percent of the are with the lowest, an increased risk of roughly 40 percent.
According to the results published in the journal JAMA Psychiatry, the link remained even after taking into account class, drug use, family history of mental illness and other factors.
“Does Not Show Cause/Effect”
The results did not show cause and effect according to Helen Fisher, senior author, also of King’s College London but she added, however:
It could be that smaller particles are getting into the brain and causing inflammation.
Highly volatile chemicals carried deep into the body by pollution could also be contributing to this problem.
“This new research builds on increasing evidence of a likely link between air pollution and mental health issues. We need a radical approach to air pollution as it is very likely damaging the mental health of young and older people alike,” said Daniel Maughan, of the Royal College of Psychiatrists.
The Study’s Significance
Director of research at the mental health charity MQ, Sophie Dix, said:
This study is significant because it provides a starting point with a possible link between pollution and psychosis. There is no evidence that pollution necessarily causes psychosis or whether this is one of many factors or acting in isolation. There is a bigger picture here but that does not diminish the importance of these findings.
“This new study makes a compelling case to investigate a range of mental health outcomes of air pollution exposure. Other variables worth studying could include academic attainment in early life stages and cognitive decline in old age due to early-life exposure to air pollution,” said Stefan Reis, of the Natural Environment Research Council Centre for Ecology & Hydrology.