Serotonin precursor effects in tardive dyskinesia.

In an attempt to determine the role of serotoninergic mechanisms in the pathophysiology of tardive dyskinesia, the serotonin precursor 5-hydroxytryptophan (5HTP) with carbidopa, a peripheral decarboxylase inhibitor, were given in a double-blind crossover design to seven patients with longstanding tardive dyskinesia. In the five patients who completed the study, there was no change in dyskinetic movements. Most of the patients had worsening of psychotic symptoms with 5HTP. The data suggest that serotonin precursors have no therapeutic effects in tardive dyskinesia. The implications for the role of serotonin in the pathophysiology of tardive dyskinesia are discussed.

RCT Entities:   Population Interventions Outcomes