Treatments for tics that have demonstrated efficacy in replicated controlled trials (RCTs) include the following:

  • Dopamine D2 receptor antagonist therapy
  • Dopamine agonist therapy
  • Habit reversal therapy

Dopamine D2 receptor antagonist therapy
In 1959, soon after its introduction, chlorpromazine was reported to dramatically improve tic severity. Since then, several allocation randomized controlled trials with various neuroleptics (eg, haloperidol, fluphenazine, pimozide) have confirmed these initial results. On average, tic severity declines by approximately 50-80% with neuroleptic treatment.

Neuroleptic drugs are the current standard in terms of efficacy in the treatment of tics. They can be effective at doses far below the usual treatment dose for psychosis, and most adverse effects are manageable with pharmacologic manipulations. Unfortunately, many patients do not tolerate acute adverse effects (most commonly sedation, weight gain, depression, lethargy, and akathisia), and prolonged treatment poses a small risk of tardive dyskinesia. Therefore, other treatments have been investigated.

Risperidone, olanzapine, and ziprasidone have been shown to produce at least as much clinical effect as a classic neuroleptic comparator, with fewer adverse effects.A small study of clozapine suggested little effect. Small studies of the dopamine D2R partial agonist aripiprazole show that it is effective for tic suppression.RCT data are not yet available, however.

Metoclopramide is a D2 receptor antagonist that is usually used for nausea. A case series and an RCT suggest it treats tics with good short-term tolerability. However, long-term use of metoclopramide has been associated with tardive dyskinesia.

Dopamine agonist therapy
Paradoxically, several mixed dopamine agonists have also been proven effective in reducing tic frequency To date, they have been tested exclusively in relatively low doses, partly because of a theory that, at these doses, they must antagonize dopamine function by selective action at presynaptic receptors.

Accumulating evidence suggests that this rationale is faulty, however, and trials with higher doses may be expected. Similarly, the present author and colleagues currently are conducting a placebo-controlled double-blind study of levodopa as a treatment for tics.

Habit reversal therapy
Five RCTs have demonstrated the efficacy of a specific form of behavior therapy for tics.The originally tested treatment consisted of a package of interventions called habit reversal therapy,which comprises monitoring, relaxation, and other nonspecific elements of behavior therapy. The most important element is application of a competing response whenever the patient notices either a tic or the urge to tic.

Initially, heavy effort on the part of the patient may be needed. However, in all 4 reported studies, at long-term follow-up at least one half of treated patients had greater than 75% reduction in overall tic severity, whether based on self-report of home tic counts or on blind review of a videotape filmed in the clinic.

The effort expended by patients decreased dramatically as tic frequency declined, usually within the first few weeks of treatment. No substitution of other tics was noted, which commonly occurs when patients substitute a volitional action on a haphazard basis