Tics are sudden, involuntary, recurring motor movements or vocalizations. They are often experienced as an irresistible urge; however, they can be suppressed for varying lengths of time. The tension felt by an individual with a tic disorder when experiencing the urge may feel as though there is an increasing amount of tension or bodily need, like the tension that comes before a sneeze or when one feels the need to scratch an itch. Individuals may emit tics in bouts of one or several, and the bouts are separated by periods of time of non-tic behaviors, which can last for several hours. Often, tics can be exacerbated during periods of stress. Tic disorders are categorized into four different disorders: Tourette’s Disorder, Transient Tic Disorder, Chronic Motor or Vocal Tic Disorder, and Tic Disorder Not Otherwise Specified.
Tics can be simple or complex. Some examples of simple motor tics include eye blinking and facial grimacing. Complex motor tics include jumping, holding unusual postures, and making hand gestures. Simple vocal tics are meaningless sounds, such as sniffing or clearing one’s throat. Complex vocal tics involve more developed speech and language. Some examples of complex vocal tics include spontaneously saying single words or phrases; sudden, meaningless changes in pitch or volume when talking; repeating one’s own sounds or words; repeating the last sounds or words that one hears.
Studies suggest that there may be a genetic component to the development of Tic Disorders, but the precise causes of tics are unknown. Not everyone who has genetic vulnerability for developing tics will express the symptoms of a tic disorder.
Tourette’s Disorder involves multiple motor tics and at least one vocal tic. They may occur simultaneously or at different periods of time during the course of the disorder. These tics will occur several times during a day and reoccur for a period of more than one year. There is not a tic-free period of time for more than 3 consecutive months during the course of Tourette’s. For about half of individuals with Tourette’s, the first symptoms to present are episodes of a single tic, usually eye blinking. For others, multiple symptoms may begin at the same time. Coprolalia is a form of Tourette’s in which an individual will utter complex motor tics that are obscenities, and this affects less than 10% of individuals with Tourette’s.
The prevalence of Tourette’s is related to age. More children are affected than adults. The age of onset may be as early as 2 years and usually occurs during childhood or early adolescence. The duration of Tourette’s may be lifelong, with periods of time when symptoms remit. The severity, frequency, and disruptiveness of symptoms often will diminish during later adolescence and adulthood, and for some, the symptoms may completely disappear during adulthood. For others, however, symptoms may get worse during adulthood. Males are 3-5 times more likely to develop Tourette’s than females.
Studies suggest that there may be a genetic component to the development of Tourette’s Disorder, but the precise causes are unknown. For some individuals with Tourette’s, there is no evidence of a familial/genetic pattern.