To receive a diagnosis of Tourette Syndrome a person must exhibit both multiple motor tics and one or more vocal tics for a period of at least one year, occurring before age twenty-one. TS affects individuals of all ethnic groups. Males are affected three to four times more often than females. Most people improve with maturity and can expect a normal life span. Tics periodically change in number, frequency, type and location.
Tics often wax and wane in severity and can sometimes disappear for weeks and months at a time.
Tics, classified as simple and complex, range from simple eye blinking and throat clearing to more complex symptoms of jumping and uttering words out of context. The majority of people with TS are not significantly disabled by their tics or behavioral symptoms. Although most people with TS can exercise some control over their tics, suppression may simply postpone more severe outbursts of symptoms. Eventually all tics must be expressed. While tension and stress can increase tic expression, concentration on an absorbing task may actually decrease the expression of tics.