Study Shows Possible Link Between ADHD and Pesticide


New research published online in the journal Environmental Health has suggested a link between commonly used household pesticide and attention-deficit hyperactivity disorder (ADHD) in children and teens.

Rick Nauert PhD., reporting for PsychCentral, writes that the relationship was correlational, not a cause and effect linkage, but the finding that pyrethroid pesticide exposure and ADHD are associated, particularly in cases of hyperactivity and impulsivity, is an important discovery. The research, carried out at Cincinnati Hospital Medical Center, found the association was stronger in boys than in girls and that inattentiveness was not associated with contact with pesticide.

“Given the growing use of pyrethroid pesticides and the perception that they may represent a safe alternative, our findings may be of considerable public health importance,” says Tanya Froehlich, M.D., a developmental pediatrician at Cincinnati Children’s and the study’s corresponding author.

The most common organophosphate pesticides were banned in 2000-2001 because of concerns about health dangers. Since then, the trend has been toward the use of pyrethroid pesticides, since they are thought to be less toxic. However, in animal studies, an increased vulnerability to the effects of pyrethroid exposure on hyperactivity, impulsivity, and abnormalities in the dopamine system in male mice was discovered. A neurochemical, dopamine, may be involved in activities that control ADHD.

Data, from the 2000-2001 National Health and Nutrition Examination Survey (NHANES) on 687 children ages 8 to 15 was examined. Measurement of pesticide exposure was measured in urine samples and ADHD was determined by the use of a diagnostic instrument. Boys with markers pointing to pyrethroid exposure were three times as likely to have ADHD when compared to boys with no detectable 3-PBA. The biomarkers were not linked with increased incidence of ADHD diagnosis or symptoms in girls.

The University Herald quoted the study’s author:

“Our study assessed pyrethroid exposure using 3-PBA concentrations in a single urine sample,” Dr. Froehlich said. “Given that pyrethroids are non-persistent and rapidly metabolized, measurements over time would provide a more accurate assessment of typical exposure and are recommended in future studies before we can say definitively whether our results have public health ramifications.”

There is an ongoing debate among educators, health-care professionals, and patient advocates over attention deficit disorder over the causes of the condition, treatments, and parenting practices. Arlene Karidis of The Washington Post writes that the label itself, ADHD, is even controversial.

Russell Barkley, a neuropsychiatrist and professor of psychiatry and pediatrics at the Medical University of South Carolina who has published more than 300 peer-reviewed articles on the condition, says:

ADHD is not simply about not being able to pay attention. Describing it as such is like calling autism a ‘not looking at people’ problem,” he said, and there is much more to ADHD.

The CDC reports that 11% of US children age 4-17 have been diagnosed with ADHD as of 2011. CHADD, a national research center for ADHD, suggests mixing supportive approaches to assist anyone with ADHD. Medication, when used after agreement between parents and children’s doctors, along with applied parenting skills, behavioral interventions, and school support when used in combination can have high rates of success.

06 3, 2015