An investigation of tic suppression and the rebound effect in Tourette's disorder.

Many patients, parents of children with Tourette's disorder, and professionals have suggested that following a period of suppression, tics will rebound to a rate that will exceed the average rate of occurrence. At present, there are no empirical data to support or refute such an effect. This experiment utilized an A-B-A design with replication to test this hypothesized effect. Following baseline observation, participants were instructed to refrain from exhibiting tics while watching videotapes, engaging in conversation, or while alone in a room with no activity. Observation continued following the suppression phase. Results of this experiment showed suppression of tics in almost one half of all sessions, with adults demonstrating suppression more frequently. Furthermore, results of this experiment failed to support a commonly held perception that following a period of voluntary suppression tics will rebound to a rate that will exceed the average rate of occurrence.