Study Links Air Pollution Exposure To Increased Risk Of Psychosis In Teens

Living in urban environments with higher exposures to air pollution may increase the likelihood of a teen experiencing psychosis, according to the findings of new research.

In a study published this week in the medical journal JAMA Psychiatry, researchers indicate that episodes of psychosis were more likely to occur among teens who had higher levels of exposures to air pollution, such as particulate matter and nitrogen dioxide and nitrogen oxides.

Researchers conducted the Environmental-Risk Longitudinal Twin Study after reviewing findings linking city living and psychosis. Children born and raised in urban environments were compared to rural settings, and found to be twice as likely to develop psychosis in adulthood. Researchers wanted to find out why.

The study involved 2,200 children born January 1994 to December 1995, in England and Wales. The children were followed up from birth to 18 years old. Researchers calculated estimates of air pollution exposure at their home addresses and their two most visited locations for nitrogen dioxide and nitrogen oxides–produced from car exhaust and burning fossil fuels–as well as particulate matter 2.5 (PM 2.5) and PM 10.

Particulate matter includes microscopic particles of pollution made up of dust, dirt, soot, and water that are 2.5 or 10 micrometers in size. In comparison, a single strand of human hair is 70 micrometers.

Study participants included a wide representation of geographic and socioeconomic composition of U.K. households. Since 90% of the world’s population live in areas with poor air quality, the findings are key.

At age 18, adolescents were privately interviewed regarding adolescent psychotic experiences. They were asked if they ever heard voices that other people could not hear, if they thought they were being followed and spied on, if they experienced or saw things other people didn’t, or had feelings of paranoia.

These symptoms are considered less extreme versions of the type of psychotic symptoms people with schizophrenia might experience.

Overall, roughly 30% of teens had at least one psychotic experience from 12 to 18 years of age. Psychotic experiences were more common among teens with the highest annual exposure to the air pollution types studied, researchers determined.

A teen was 71% more likely to have an episode of psychosis if they were exposed to nitrogen dioxide. Similarly, they were 72% more likely if they were exposed to nitrogen oxides, and 45% more likely after exposure to PM 2.5.

Furthermore, city settings increased a teen’s risk of psychosis by 94%. The risk decreased when a teen lived in suburban areas and decreased more in rural settings.

Researchers also accounted for other factors, including marijuana dependence, cigarette smoking, and neighborhood crime.

Air pollution has been linked to a range of health problems, including increased risk of kidney disease and reduced life expectancy. Similarly, prenatal exposure increases the risk of autism and is known to negatively affect fetal heart development.

One explanation for the increased risk may not be linked to air pollution from increased road traffic and other burning fuels. Instead, it may be linked to noise pollution in city settings. The increased noise experienced in the city may cause disturbed sleep for teens. Disturbed sleep leads to stress and both are associated with psychosis.

However, researchers noted, if the link is related to air pollution specifically, the pollution particles may be causing inflammation in the brain. Inflammation is known to stunt brain development in severe cases.

More so, some of these factors may be working in conjunction to cause the increased risk of psychosis. It may be air pollution in tandem with noise pollution leading to a collective outcome.

Recent research linked air pollution exposure during infancy to brain developmental issues. Since 75% of all mental health problems begin during adolescence, researchers say it is imperative to investigate the link further to find ways to decrease the risk for teens and children.