Epidemiology of Tics

As we described elsewhere, tics are defined as “sudden, rapid, recurrent, nonrhythmic, stereotyped motor movements or vocalizations”and have clinical concerns1.Tics are likely to differ in terms of the body location, number, frequency, complexity, intensity or forcefulness, noticeable and resulting social consequences2. Intervals between tics can range from seconds, hours or even days. The forcefulness with which a tic is performed can range from slight and barely noticeable to intense and obvious. Over time, the frequency and intensity of tics may wax and wane and maybe influenced by a variety of internal and external stimuli including private events, contextual variables and social reinforcement contingencies3.