What is ADHD?

Attention deficit hyperactivity disorder (ADHD) is a problem that starts in young children with hyperactivity, impulsivity, and/or inattention. For these problems to be diagnosed as ADHD, they must be greater than normally seen in a child of that age and development. ADHD affects millions of children and is the most commonly diagnosed mental health disorder in childhood.

ADHD includes some combination of problems such as difficulty sustaining attention, over-activity and impulsive behavior. Children with ADHD struggle with school performance, social relationships, emotional problems and low self-esteem. While there is no cure for ADHD, treatment with medication and/or behavioral therapy can help a great deal with the symptoms. In 30-60% of children diagnosed with ADHD, symptoms will continue into adulthood.

Causes and Risk Factors

ADHD affects about 3 - 16% of school aged children and is diagnosed much more often in boys than in girls. Every child suspected of having ADHD should be evaluated carefully by a doctor to rule out other conditions or reasons for the behavior. Depression, lack of sleep, learning disabilities, seizures and tic disorders may cause similar symptoms. Many children with ADHD also have at least one other developmental or behavioral problem.

Parents sometimes feel it is their fault when a child is diagnosed with ADHD, but the causes are more likely to be genetic than choices made by parents. At the same time, the environment a child is in may contribute to or worsen their behavior. While the disorder may run in families, it is not clear exactly what causes it although it seems to start early in life as the brain is developing. Some of the causes being studied are:

• Altered brain structure and function – brain scans have revealed important differences in the brain activity of people with ADHD. For example, there appears to be less activity in the areas of the brain that control activity levels and attention.
• Genetics – ADHD tends to run in families and several genes that may be associated with ADHD are currently being studied.
• Smoking, drug use and exposure to toxins during pregnancy – Pregnant women who smoke cigarettes have a higher risk of having children with ADHD. Pregnant women who are exposed to environmental toxins may also be more likely to have children with ADHD. Alcohol or drug use during pregnancy may lower the activity of the nerve cells (neurons) that produce neurotransmitters and so increase the risk of ADHD. Smoking and drug use during pregnancy also causes babies to be born at lower birthweights and this in turn is also linked to ADHD.
• Childhood exposure to environmental toxins – Preschool children exposed to certain toxins have a higher risk of developmental and behavioral problems. Exposure to lead, which is found mainly in paint and pipes in older buildings, has been linked to disruptive behavior, agression and to a short attention span.
• Food additives – Substances added to food, such as artificial coloring or food preservatives, may contribute to hyperactive behavior. Although sugar is a popular suspect in causing hyperactivity, there's no reliable evidence for this.