Tourette's syndrome is a common childhood-onset hereditary neurological and behavioral disorder. It is characterized by the presence of both motor and vocal tics. Tics are sudden, rapid, repetitive, non-rhythmic, intermittent movements or movement fragments that are almost always briefly suppressible and are usually associated with awareness of an urge to perform the movement. The tics in Tourette's syndrome can be simple or complex. Tourette's syndrome is also associated with several psychiatric disorders. The most common of these are attention deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). In some instances, these psychiatric disorders may impact quality of life more than the tics themselves.
The severity of this disease varies from patient to patient. While some patients have a very mild form of Tourette's syndrome, many of them may have it severe enough to interfere with their ability to participate in school and other important activities of childhood and adulthood. The cause of Tourette's syndrome is unknown, and the genetic basis of this disease also remains a mystery.
In addition to Tourette’s syndrome, there are other related tic disorders. These include transient tic disorders that last less than a year, and chronic tic disorders that may consist of simple or complex motor tics, or vocal tics. These tic disorders commonly have onset in childhood but may also have onset in adulthood. Other tics may be a consequence of medications.