ADHD, known as attention-deficit hyperactivity disorder, affects millions of children each year and is a disorder for which no cure exists. According to MayoClinic.com, doctors prefer to use the term ADHD when referring to both ADHD and ADD--attention deficit disorder--because ADHD includes the primary characteristics of the disorder, which are inattention and hyperactivity. While researchers still have a lot to learn about the cause of the disorder, many contributing factors have been identified.
Exposure to Toxins in Utero
Mothers who choose to smoke, drink alcohol or abuse drugs while pregnant may be putting their unborn children at risk for developing ADHD, as MayoClinic.com warns. Alcohol and drug abuse during pregnancy may reduce the activity of the nerve cells in the brain of the fetus that produce neurotransmitters, or chemical messengers. In addition, pregnant women exposed to environmental poisons, such as PCBs, are also more likely to give birth to children with ADHD. PCBs are industrial chemicals that were popular in the 1970s.
Lead Poisoning
Lead is an environmental toxin found mainly in the paint and pipes of older buildings. Healthcommunities.com states that there is a connection between ADHD and infants and children who suffer from exposure to paint containing lead. Lead paint can cause poor concentration, irritability and distractedness.
Heredity
MayoClinic.com states that ADHD tends to run in families with approximately one in four children with this disorder having at least one relative with the disorder. Healthcommunities.com concurs, explaining that at least two genes are associated with ADHD. The site adds that children whose parents have this disorder are three times more likely than other children to develop it themselves.
Brain Anatomy
A difference in brain structure and activity of a person with ADHD appears to exist, playing a contributing factor in the development of ADHD. MayoClinic.com states that there seems to be less activity in the areas of the brain responsible for both attention and activity in those with ADHD. Healthcommunities.com adds that computer imaging of the brain shows a reduction of frontal lobe activity in a person with ADHD. This area is responsible for attention, planning, organizing and impulse control.
Learning Disabilities
There may be a connection between people who have learning disabilities and ADHD. The National Institute of Mental Health estimates that 20 to 30 percent of those with a learning disability also suffer from ADHD, while 70 percent of people with Tourette's syndrome have a dual diagnosis, as well.
