Home > Encyclopedia of Mental Disorders > Tic disorders

Definition

Tic disorders are characterized by the persistent presence of tics, which are abrupt, repetitive involuntary movements and sounds that have been described as caricatures of normal physical acts. The best known of these disorders is Tourette's disorder, or Tourette's syndrome.

Description

Tics are sudden, painless, nonrhythmic behaviors that are either motor (related to movement) or vocal and that appear out of context- for example, knee bends in science class. They are fairly common in childhood; in the vast majority of cases, they are temporary conditions that resolve on their own. In some children, however, the tics persist over time, becoming more complex and severe.

Tics may be simple (using only a few muscles or simple sounds) or complex (using many muscle groups or full...