A. No one knows for sure whether the prevalence of ADHD per se has risen, but it is very clear that the number of children identified with the disorder who obtain treatment has risen over the past decade. Some of this increased identification and increased treatment seeking is due in part to greater media interest, heightened consumer awareness, and the availability of effective treatments. A similar pattern is now being observed in other countries. Whether the frequency of the disorder itself has risen remains unknown, and needs to be studied.
Q. Can ADHD be seen in brain scans of children with the disorder?
A. Not directly, no. But neuroimaging research has shown that the brains of children with ADHD differ fairly consistently from those of children without the disorder in that several brain regions and structures (pre-frontal cortex, striatum, basal ganglia, and cerebellum) tend to be smaller. Overall brain size is generally 5% smaller in affected children than children without ADHD.
While this average difference is observed consistently, it is too small to be useful in making the diagnosis of ADHD in a particular individual. In addition, there appears to be a link between a person’s ability to pay continued attention and measures that reflect brain activity. In people with ADHD, the brain areas that control attention appear to be less active, suggesting that a lower level of activity in some parts of the brain may be related to difficulties sustaining attention.
Q. Can a preschool child be diagnosed with ADHD?
A. The diagnosis of ADHD in the preschool child is possible, but can be difficult and should be made cautiously by experts well trained in childhood neurobehavioral disorders. Developmental problems, especially language delays, and adjustment problems can sometimes imitate ADHD. Treatment should focus on placement in a structured preschool with parent training and support. Stimulants can reduce oppositional behavior and improve mother-child interactions, but they are usually reserved for severe cases or when a child is unresponsive to environmental or behavioral interventions.
Q. What is the impact of ADHD on children and their families?