Is there a direct relationship between conduct disorder and ADHD, and what percentage of children with ADHD have conduct disorder?

Conduct disorder is characterized by problems with the law, or what we call delinquent behavior. There is a clear overlap in studies of these disorders. Estimates indicate that anywhere from 20 to 70 percent of children who have ADHD also have conduct disorder. Children with conduct disorder almost always have ADHD. That has been a big problem for the whole field because people have often felt the conduct disorder was a sociological phenomenon and ADHD appears to be risk factor for developing antisocial behavior.

Do stimulant medications affect a child's growth?

We have not been studying the effect of medication on growth, but one psychiatric journal reported that ultimate height is not affected by stimulant medication. In some children, stimulant medicines can slow down the growth process, but when children are taken off the drug, growth rebounds.

Is there any evidence to support the claim that some ADHD treatment medications might cause tics or Tourette syndrome?

Tourette is a disorder characterized by facial tics, such as eye blinking, facial twitches, shoulder or head twitches, vocal tics, throat clearing, sniffling, or grunting, which are all involuntary. Fifty percent of children with Tourette syndrome, or tic disorders, will have ADHD regardless of treatment with stimulant medication. In studies of genetically identical twins, only one of each twin pair was treated with stimulant medication, yet all the twins developed Tourette. Stimulants most likely do not cause Tourette. The data seem to indicate that stimulant medication may delay the onset of Tourette, if anything.

Are there any studies on female children, and what is the difference between the way girls with ADHD and boys with ADHD act?

There are about four to six studies on hyperactive girls that indicate that girls generally have the same symptoms as boys. No one can really understands why the described referral rate for boys is higher. Many young girls have ADHD as severe as that of boys. Hyperactive girls are being studied much more commonly now.

A parent of an ADHD child recently wrote an article on the pros and cons of medication - particularly Ritalin, a drug said to cause depression in children. Have you found this to be the case?

There is no question that stimulants, when used in high doses or in particularly sensitive kids, can make children irritable, moody, and sad. The good news is that the medication wears off quickly, usually within three to four hours. Once the medication has worn off, a child's mood returns to normal and then the dosage should be reduced to eliminate further side effects.