This document discusses tic disorders, including Tourette's disorder. It defines tics as involuntary muscle contractions or vocalizations. There are simple and complex motor and vocal tics. Tourette's disorder is characterized by both multiple motor and at least one vocal tic for over a year. Onset is before age 18. It occurs more in males than females and is associated with ADHD and OCD. While the cause is unknown, dopamine and endogenous opioids may play a role. Treatment includes haloperidol. Transient tic disorder involves single or multiple tics for less than a year.