The lead author of a new study helps explain his recent research on children with tics and ADHD.
Attention deficit hyperactivity disorder (ADHD) is probably the most common medical condition that challenges children's success in school.
The disorder is characterized by impaired attention and concentration, impulsive behavior, easy distractibility and hyperactivity.
While it is well-known that ADHD tends to respond to a medication known as Ritalin (methylphenidate), doctors have believed for decades that Ritalin should not be prescribed for children who have ADHD in combination with tics, since the drug might worsen this condition.
The evidence to support this idea, however, has been unproven.
Tics Are Common
Tics are involuntary twitches, such as eye blinking, head jerking, facial grimacing, or involuntary noises, such as throat clearing, grunting or sniffing.
Children who have multiple and chronic tics are diagnosed as having Tourette's syndrome.
It is quite common for children to have both ADHD and tics, leaving doctors in a difficult position regarding how to treat such patients.
Furthermore, the most commonly used alternative to Ritalin, clonidine, had not yet been proven to be effective.
Surprising Study Results
The Tourette's Syndrome Study Group, a collaborative research group involving 12 medical centers in the U.S., studied the effects of Ritalin and clonidine on 136 children who had both ADHD and tics.
The study, whose results are being reported in today's edition of the medical journal Neurology, used methods to prevent bias, including an inactive placebo pill and a "double-blind" design whereby neither the child nor the evaluators knew which medicine was being given.
The researchers found that, contrary to earlier beliefs, Ritalin did not worsen tics.
In addition, both Ritalin and clonidine were highly effective in improving the symptoms of ADHD.
Ritalin seemed to be most helpful for inattention and hyperactivity, while clonidine did particularly well for impulsivity and hyperactivity.
A more complete coverage of the ADHD symptom spectrum may explain why the combination of the two drugs was more effective than either medicine used alone.
Clonidine did cause drowsiness in several patients, but otherwise the medicines were well-tolerated.
This study does not support prior recommendations to avoid Ritalin to treat ADHD in children with tics.
It also has confirmed the benefit of clonidine for ADHD and raises the possibility of customizing medications to target individual symptoms that are most bothersome for a given child with the disorder.
Roger Kurlan, M.D. is a professor of neurology at the University of Rochester Medical Center, and principal investigator of The Tourette's Syndrome Study Group.