CDC Features

CDC Features

Tourette Syndrome: Involuntary Motor and Vocal or Phonic Tics

Tourette Syndrome is an inherited, neurological disorder. Learn more about how it is diagnosed and how many people have it.

Tourette Syndrome is an inherited, neurological disorder characterized by involuntary movements, called motor tics, and uncontrollable vocalizations, called vocal or phonic tics. A tic is a sudden rapid, recurrent, non-rhythmic, stereotyped motor movement or vocalization. [1]

How is Tourette Syndrome Diagnosed?

Diagnosis is made by observing symptoms and evaluating the history of their onset. No blood analysis, X-ray or other type of medical test can identify this condition. [2]

According to the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders: [3]

Both motor and vocal tics are present during the illness, although not always at the same time.
The tics occur many times a day (usually in bouts) nearly every day or off and on for more than 1 year, with never a tic-free period of more than 3 months in a row.
The onset of Tourette Syndrome occurs before 18 years of age.
The disturbance is not caused by the direct physiological effects of medications or other substances, and is not the result of a general medical condition (e.g., seizures, Huntington's disease or postviral encephalitis).

How Many People have Tourette Syndrome and Who is Affected by it?

Community-based studies that include previously unidentified cases have reported estimates of 6-8/1000 children with Tourette Syndrome. The first-ever national estimate among a nationally representative sample of U.S. children revealed that 3 out of every 1000 children between the age of 6 and 17 in the United States have been diagnosed with Tourette Syndrome, according to a new study by the Centers for Disease Control and Prevention released in the Morbidity and Mortality Weekly Report. Because this estimate is based on parent report of a Tourette Syndrome diagnosis, and diagnosis is less likely for children with limited access to health care services, this prevalence estimate is likely an underestimate of all the children who actually have Tourette Syndrome.

The new study, "Prevalence of Diagnosed Tourette Syndrome in Children in the United States, 2007," found that a Tourette Syndrome diagnosis is three times more common in boys than in girls, and approximately twice as common in children between 12-17 years as those aged 6-12 years. Among children with TS, 27% were reported as having moderate or severe Tourette Syndrome and 79% of children had also been diagnosed with at least one additional mental health or neurodevelopmental condition. The most common co-occurring condition was Attention-Deficit/Hyperactivity Disorder.[4]

The onset of Tourette Syndrome typically occurs when a child is 6 to 8 years old. Although Tourette Syndrome and tics might appear, disappear, and reappear, it is considered a chronic condition.

Tourette Syndrome and related disorders can place individuals at higher risk for learning, behavioral and social difficulties. Many studies have linked Tourette Syndrome and tic disorders to higher rates of attention deficit/hyperactivity disorder, obsessive-compulsive disorder, and impairments associated with these co-occurring conditions.

References:

National Institute of Neurological Disorders and Stroke Tourette Syndrome Fact Sheet.
Tourette Syndrome Association Tourette Syndrome Fact Sheet.
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Washington, DC, American Psychiatric Association: 2000.
CDC. Prevalence of Diagnosed Tourette Syndrome in Children in the United States, 2007. MMWR 2009;58:581-5