OBJECTIVES: I. Determine whether the time period between randomization and endpoint is longer in the short term pimozide therapy or longer term therapy in patients with Tourette syndrome.

II. Determine whether tic severity, medication side effects, academic performance and psychosocial functioning are better in the short term pimozide therapy or longer term pimozide therapy.

PROTOCOL OUTLINE: This is a combined open label and double blind randomized study.

Patients receive pimozide (open label) orally until a stable level of tic control is achieved and remains unchanged for at least 1 month.

Then, patients are randomized to one of two possible double blind treatments. In the short term pimozide group, patients receive pimozide over 2 weeks. Then, pimozide is gradually replaced by an inactive placebo within the following 10 weeks.

Patients in the long term pimozide group receive pimozide. Patients continue treatment for 12 months or until a worsening of tics or behavioral symptoms are present for which an increased dosage is required.

Patients who do not experience an exacerbation of tics requiring an increase in dosage are followed for 1 year from the date of entry.

PROTOCOL ENTRY CRITERIA:

--Disease Characteristics-- DSM-III-R criteria for Tourette syndrome Chronic motor tic disorder with tics sufficiently severe to require neuroleptic therapy --Prior/Concurrent Therapy-- No clonidine for at least 2 weeks or any neuroleptic (e.g., haloperidol, pimozide) within 3 months prior to study Stable dosage of other medications (e.g., antiobsessional, stimulant) for at least 3 months prior to and during study required