Prenatal Exposure to Pollutants May Up ADHD Symptoms, Depression Risk
(HealthDay News) — Exposure to common air pollutants before birth may make children more likely to have the symptoms of attention-deficit/hyperactivity disorder (ADHD) and other thinking and behavioral problems, a small new study suggests. The findings were published online March 25 in JAMA Psychiatry.
Bradley Peterson, MD, of the Institute for the Developing Mind at The Saban Research Institute of Children's Hospital Los Angeles, and colleagues have been following 620 minority women who live in New York City. The researchers are planning to eventually scan 250 children born to the women, gathering information about the mothers' exposure to air pollutants during pregnancy and after. For the new study, Peterson told HealthDay: "We selected out 40 who had minimal exposure to other substances we know produce brain problems," so the team could focus on the effects of the pollutants polycyclic aromatic hydrocarbons (PAHs).
The children in the study have been followed from before birth through ages 7–9. The children and their mothers enrolled during the years 1998–2006. The researchers used magnetic resonance imaging to measure the children's brains and tested the children to see if they had symptoms related to ADHD or other problems. The researchers found that prenatal exposure to the pollutants was linked with thinking and behavioral problems. The greater the exposure, the worse the brain changes and the more likely the children were to have ADHD symptoms or other issues.
In earlier research, the team had found that exposure to PAHs during gestation was linked with several problems, including developmental delays by age 3, reduced verbal IQ at age 5, and anxiety and depression by age 7. In the new study, the researchers found reductions in the white matter surface of the brain's left hemisphere. This type of reduction is linked to slower processing of information during IQ tests and more severe problems in behavior, including ADHD symptoms and aggression, the researchers said. Being exposed after birth was linked to additional white matter changes linked to problems in concentration and problem-solving ability.