June 4, 2009 -- Tourette's syndrome afflicts three out of every 1,000 children between ages 6 and 17 in the United States, the CDC says in its first-ever estimate of the prevalence of the neurological disorder.
The findings are revealed in the June 5 edition of the CDC’s Morbidity and Mortality Weekly Report.
According to the MMWR study, Tourette's syndrome is three times more common in boys than in girls, and about twice as common in children 12 to 17 as in those 6 to 11.
Twenty-seven percent of children with Tourette's syndrome have moderate or severe cases, the study says, and 79% of youngsters who have it also have been diagnosed with at least one additional mental health or neurodevelopmental condition.
Tourette's syndrome typically starts in childhood and is characterized by recurring multiple motor tics, and at least one vocal tic. Symptoms are generally most severe between 10 and 12 years of age and lessen by adulthood.
These are involuntary, repetitive, stereotyped, usually sudden and rapid movements or vocalizations that may be suppressed for short periods of time, the CDC report says.
“TS [Tourette's syndrome] and tic disorders have been linked to higher rates of attention deficit/hyperactivity disorder, obsessive-compulsive disorder, and impairments associated with these conditions, such as learning disabilities and problems with peer relations,” says Rebecca Bitsko, MD, health scientist at the CDC, in a news release.
She says because so many children with Tourette's also have other neurological or mental health problems, the relationship between the conditions warrant further study.
Non-Hispanic white children were more than twice as likely as non-Hispanic black children or Hispanic children to have a parent-reported case of Tourette's syndrome.
“Having an estimate of the number of U.S. children who are diagnosed with TS is a first step toward understanding the overall impact of this condition in the population,” Bitsko says. “Further research must examine differences in access to health care for children with TS in different population groups, the impact of TS on the quality of life, long-term outcomes for children with TS, and strategies for reducing the impact of conditions associated with TS.”
Researchers examined National Survey of Children’s Health data from parents or guardians for 64,034 children 6-17 years old between April 2007 and July 2008.
The NSCH was the first large, national, population-based survey of U.S. children less than 18 years old that included questions about Tourette's syndrome.