Age at onset. Age at onset is always during childhood or early adolescence, and may be as early as two years of age. The tics may disappear permanently, or recur, especially during periods of stress. In rare cases, after a period of partial remission, the person may develop either Tourette's Disorder or Chronic Motor or Vocal Tic Disorder. However since these surveys do not specify a minimum or a maximum duration, it is not known how applicable these findings are to the prevalence of Tic Disorders.
Most studies find the disorder three times more common in males than in females.
Tic Disorders are apparently more common in first-degree biological relatives of people with Transient Tic Disorder than in the general population. In Tourette's Disorder and Chronic Motor or Vocal Tic Disorder, the duration of the disturbance is at least one year. The tics occur many times a day, nearly every day for at least two weeks, but for no longer than twelve consecutive months. C. No history of Tourette's or Chronic Motor or Vocal Tic Disorder. D. Onset before age 21.