Prevalence
A large, community-based study suggested that over 19% of school-age children have tic disorders; the children with tic disorders in that study were usually undiagnosed.
As many as 1 in 100 people may experience some form of tic disorder, usually before the onset of puberty. Tourette syndrome is the more severe expression of a spectrum of tic disorders, which are thought to be due to the same genetic vulnerability. Nevertheless, most cases of Tourette syndrome are not severe. Although a significant amount of investigative work indicates genetic linkage of the various tic disorders, further study is needed to confirm the relationship.
Read more about this topic: Tic Disorder
Famous quotes containing the word prevalence:
“That the public can grow accustomed to any face is proved by the increasing prevalence of Keiths ruined physiognomy on TV documentaries and chat shows, as familiar and homely a horror as Grandpa in The Munsters.”
—Philip Norman, British author, journalist. The Life and Good Times of the Rolling Stones, introduction (1989)
“The prevalence of suicide, without doubt, is a test of height in civilization; it means that the population is winding up its nervous and intellectual system to the utmost point of tension and that sometimes it snaps.”
—Havelock Ellis (18591939)