This document discusses tic disorders such as Tourette's disorder. It defines tics as involuntary muscle contractions or vocalizations. Tourette's is characterized by both multiple motor and at least one vocal tic over a period of more than one year. Onset is before age 18. It occurs more in males than females and is associated with ADHD and OCD. Treatment includes haloperidol. Differential diagnoses include chronic motor or vocal tic disorder and transient tic disorder.