Contact: Joel Nigg, Psychology, (517) 432-4894 or 203-4941, nigg@msu.edu; or Tom Oswald, University Relations, (517) 355-2281, oswald@msu.edu

8/30/2005

EAST LANSING, Mich. – A team of researchers from Michigan State University will be using two grants totaling nearly $3.5 million to determine if environmental contaminants, as well as hormonal influences, play a role in attention deficit hyperactivity disorder (ADHD) in children.

The largest of the grants – $3 million from the National Institutes of Health – will focus on genetics, said researcher Joel Nigg.

“The fact that genetics play a role in ADHD has been pretty well established,” said Nigg, a professor in MSU’s Department of Psychology. “What we’re doing is looking more closely at which genes might be involved.”

The researchers, which include faculty from MSU’s Department of Microbiology and Molecular Genetics, are using a new technique known as haplotype mapping.

“It’s kind of like increasing the power on a microscope,” Nigg said. “We get to look at the genes a little more closely, getting a truer picture of which variants are in play.”

The second grant, also from the NIH, totals around $400,000 and will be used to study potential links between hormones and environmental pollution and ADHD.

“ADHD is a lot more common in boys,” Nigg said. “Plus, there are some researchers who think girls with ADHD have more cognitive impairment than boys with ADHD, suggesting that a lot more has to go wrong before a girl manifests the disorder.

“Maybe hormones somehow either protect girls or amplify the problem in boys,” he said.

This grant will also allow Nigg and colleagues to investigate any links that may exist between ADHD and environmental pollutants, including inorganic compounds such as lead and mercury, and organic toxins such as PBB, PCBs and dioxins. The Michigan Department of Community Health is providing laboratory support for the study.

There is a hypothesis, Nigg said, that during prenatal neural development these contaminants occupy hormone receptors.

“So the hypothesis is that cognitive development is slightly thrown off track by virtue of the fact that instead of getting, say, estrogen, they get PCBS and the brain doesn’t develop right,” he said. “The contaminant occupies the receptors, but it obviously doesn’t fulfill the proper function.”

ADHD or other subtle learning problems may be one result in some instances.

Nigg said there are several animal studies which indicate that early exposure to average background levels of common pollutants such as PCBs result in subtle cognitive problems later in development.

As part of this project, the scientists are also beginning to gather preliminary data on the role that hormonal development may play in eating disorders.

“Both ADHD and eating disorders have theorized hormonal and genetic influences, and both show strong gender differences in developmental risk,” Nigg said.

Patients are needed for both research projects. Eligibility requirements include being between the ages of eight and 17 and having at least one biological parent able to participate. All participants will be required to submit a cheek swab or a blood sample. They also will receive a full array of psychological and diagnostic tests, including a memory test, as well as tests on ability to focus attention and ability to learn and remember.

For additional information, contact the research office at (517) 432-4894 or e-mail leslieli@msu.edu. Additional information is also available on the Web at www.msu.edu/user/nigg/nigg.htm