Tic disorders, including the most widely known Tourette syndrome (TS), are neurobehavioral disorders that begin in childhood or adolescence. The primary feature of each of these entities is the presence of motor and/or vocal tics. Although these disorders are common, there remains an ongoing search for a clearer understanding of their etiology and neurobiology. The impact of tics can be quite variable, ranging from minimal to devastating, depending on their psychosocial and physical impact. Tics rarely appear in isolation.