Psychotic experiences are more common among teenagers in areas of high air pollution, new research suggests.
Around a third (30%) of adolescents reported hearing or seeing something that wasn’t there or feelings of paranoia on at least one occasion between the ages of 12 and 18, a study published in journal JAMA Psychiatry found.
These experiences were more prevalent among teenagers exposed to places with the highest levels of pollutants, particularly nitrogen dioxide and nitrogen oxides.
Psychotic experiences are less extreme forms of symptoms experienced by people with disorders like schizophrenia, and more common in adolescence than adulthood.
They can be linked to the development of psychotic disorders and other mental health problems.
The researchers, from King’s College London, used data from 2,232 children born in England and Wales, who were assessed at the age of 18 for psychotic experiences.
This was linked with hourly estimates of air pollution at their home addresses and two other locations where they spent a lot of time at the age of 17 such as a school.
“This study found that psychotic experiences were significantly more common among teens exposed to higher levels of air pollution,” lead author Dr Joanne Newbury said.
“For example, teenagers exposed to the highest levels of nitrogen oxides had a 72% greater odds for psychotic experiences compared to those with lower exposure.
“This means that in areas with the highest levels of nitrogen oxides, there were 12 teens who reported psychotic experiences for every 20 teens who did not report psychotic experiences.
“In contrast, in areas with lower levels of nitrogen oxides, there were only seven teens who reported psychotic experiences for every 20 teens who did not report psychotic experiences.”
Adolescents exposed to the highest level of nitrogen dioxide had 71% greater odds of having a psychotic experience, the study also found.
Meanwhile, those exposed to the highest levels of particulate matter, which can include carbon, liquids, metals and dust, had 45% greater odds.
Previous research has shown a link between urban living and adolescent psychotic experiences, but the researchers said this is the first evidence of an association with air pollution levels.
Other studies have recently shown an association between dementia and air pollution levels, as well as strokes.
Some theories suggest that small particles from air pollution can enter the brain and cause inflammation or cause chemicals to enter the body, the researchers said.
“There seems to be some link between potential exposure to air pollution and effects in the brain and this is perhaps another example of that,” co-author Professor Frank Kelly said.
The researchers warned that the findings do not show that air pollution caused adolescent psychotic experiences.
They suggest that noise pollution, often found in areas of high air pollution, could also explain the results.
“We know traffic is noisy, and we know noise can disrupt sleep, and it can also be very stressful for people and both of those things have been associated with these types of psychotic experiences as well,” senior author Dr Helen Fisher said.
Dr Daniel Maughan, associate registrar for sustainability at the Royal College of Psychiatrists, said: “While the paper has not proved air pollution causes psychosis, the findings are concerning as they suggest that increased psychosis rates in urban areas are potentially linked to air pollution.
“We need a radical approach to air pollution as it is very likely damaging the mental health of young and older people alike.”
