Jason Richardson, Ph.D.; W. Michael Caudle, Ph.D.; Deborah Cory-Slechta, Ph.D.; Gary Miller, Ph.D.; Stuart L. Shalat, Sc.D.
Rutgers Robert Wood Johnson Medical School, Emory University, University of Rochester Medical Center
NIEHS Grants R21ES013828, R01ES015991, P30ES005022, T32ES012870, R01ES012702, T32ES007148, U54ES012068, R21ES012315, R01ES020415
NIEHS-funded research in humans and mice provides new evidence that early exposure to the commonly used pyrethroid pesticide known as deltamethrin may be a risk factor for attention deficit hyperactivity disorder (ADHD).
Although there is strong scientific evidence that genetics plays a role in susceptibility to ADHD, no specific gene has been identified, leading scientists to believe that environmental factors may also contribute to development of the disorder. To mimic exposures in pregnant women, the researchers exposed female mice to deltamethrin during pregnancy and lactation. The pups exhibited features of ADHD, including hyperactivity, impulsive behavior, and problems with working memory and attention. Similar to what is seen in children with ADHD, the male mice were more affected than females. The ADHD-like behaviors in the mice lasted through adulthood, even though the pesticide could no longer be detected in their systems. The researchers also observed increased dopamine transporter and receptor levels in the pups, which they say are likely responsible for the ADHD-like behaviors.
The researchers also looked at pyrethroid pesticide exposure in children using data from the National Health and Nutrition Examination Survey. An analysis of health care questionnaires and urine samples from 2,123 children and adolescents revealed that children with higher pyrethroid pesticide metabolite levels in their urine were more than twice as likely to be diagnosed with ADHD.
Citation: Richardson JR, Taylor MM, Shalat SL, Guillot TS 3rd, Caudle WM, Hossain MM, Mathews TA, Jones SR, Cory-Slechta DA, Miller GW. 2015. Developmental pesticide exposure reproduces features of attention deficit hyperactivity disorder. FASEB J; doi:10.1096/fj.14-260901fj [Online 28 January 2015].