Teen psychosis linked to air pollution in cities for first time

Air pollution may explain why city teens are twice as likely to suffer psychosis as those in rural areas.

There’s mounting evidence that dirty air can do far-reaching damage to the brain and lungs.

Teenagers living on polluted roads are about 40 per cent more likely to be psychotic, the first study of its kind finds.

Air pollution goes a long way to explaining why adolescents in cities are twice as likely to suffer psychosis as those in rural areas, researchers said.

While the study does not prove that traffic fumes cause psychosis, experts said it added to mounting evidence that dirty air can do far-reaching damage to the brain and lungs.

Fine particles and nitrous oxides in the air have long been known to cause breathing and heart problems. Evidence is emerging that they can contribute to depression and dementia.

In the latest study, researchers have used data on 2232 teenagers in England and Wales who were asked about psychotic experiences, such as whether they heard voices or felt they were being watched. About a third had such experiences. While most will grow out of them, these teenagers are at higher risk of going on to suffer full-blown psychosis.

The answers were compared with detailed modelling of pollution levels at the teenagers’ homes. Joanne Newbury, of King’s College London, lead author of the paper, said that psychotic experiences were significantly more common among teenagers exposed to higher levels of air pollution.

“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,” she said.

This means that 38 per cent of adolescents reported psychotic experiences in the quarter of areas with the highest nitrous dioxide levels, compared with 27 per cent of the quarter with the lowest, an increased risk of roughly 40 per cent.

The link remained significant even after this was adjusted for class, drug use, family history of mental illness and other factors, according to results presented in the journal JAMA Psychiatry.

Helen Fisher, senior author, also of King’s College London, said that the results did not show cause and effect. 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.

Daniel Maughan, of the Royal College of Psychiatrists, said: “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.”

Sophie Dix, director of research at the mental health charity MQ, 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.”

Stefan Reis, of the Natural Environment Research Council Centre for Ecology & Hydrology, said: “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.”

The Times