For years, scientists have focused on the genetic basis of attention deficit/hyperactivity disorder (ADHD), and for good reason. Previous data has implicated heredity as a possible source for nearly 70% of the attention problems and hyperactivity in children. Now, however, new research is pointing to lead as a potential culprit.

Over the past century, ADHD has been studied exhaustively because its impact on society is significant, leading to accidents and possible injury, poor academic performance, substance abuse, and antisocial behavior. Despite the focus, however, its root causes still remain a bit of mystery. Not too long ago, ADHD was not even considered a genuine condition, and was deemed at times a figment of people’s imaginations. Now it is considered one of the most significant learning and developmental issues affecting children today.

Lead is a well-known concern of virtually every parent out there because of its devastating effect on a child’s development. Because of lead's hazardous potential, numerous measures have been undertaken to remove it from our lives, although total eradication has been unsuccessful. Trace amounts can still be found throughout our surroundings, from imported toys and jewelry, and even in our drinking water. In fact, almost all of us, including children, have some trace amounts of lead in our bodies.

The prevalence of lead in children therefore makes it a potential candidate as a contributor to ADHD, and two recent studies have lent some credibility to this theory. In both studies, elevated amounts of lead in the blood of children were tied to higher levels hyperactivity and lack of impulse control, and in certain instances, problems with attention. The connection was determined to be independent of IQ, family income, race, or maternal lifestyle habits (specifically smoking) during pregnancy.

Researchers cited a potential physiological basis for their findings. Lead is a well-known neurotoxin that affects the activity and development of neurons in the striatum and frontal cortex. As it disrupts activity in these areas, it can affect cognitive abilities in a way that negatively influences impulse control and hyperactivity.

The American Medical Association (AMA) has designated ADHD as a mental illness that entails difficulty in paying attention as well restlessness and impulsive behavior. It generally appears around the age of 3 years, though diagnosis usually does not occur until the age of 6 or 7. Its presence can make home and school life challenging for the child. Though it can resolve itself during adolescence, it usually lasts into adulthood and can affect a person throughout their lifetime.

The prevalence of ADHD has been estimated to be about 8% of the population, though some experts put that number as high as 25%. The condition seems to affect boys more than girls, though that gap is narrowing. In fact, ten years ago, 10 times as many boys were thought to have ADHD as girls, but now difference is now believed to be 3 to 5 times. Over that time, the number of children who were prescribed Ritalin, the stimulant designed to help control ADHD, has nearly tripled.

The relationship between ADHD and learning are significant. Nearly 2 out of every 10 children with ADHD have learning disabilities, and 8 out of every 10 are academic underachievers. ADHD has also been linked to problems with self-esteem, depression, hostility, and anxiety.

If you suspect that your child might have ADHD, consult with your pediatrician. For more information, visit the website for Children and Adults with Attention Deficit/Hyperactivity Disorder (CHADD) and the Center for Disease Control and Prevention (CDC).

For more information about lead poisoning, visit the website for Kid's Health.