METHYLPHENIDATE RESPONSE, PSYCHOPATHOLOGY AND TARDIVE-DYSKINESIA AS PREDICTORS OF RELAPSE IN SCHIZOPHRENIA

Despite the proven efficacy of acute and maintenance pharmacotherapy i n schizophrenia, practical methods for identifying patients who requir e continuous treatment to prevent relapse have not been established. W e hypothesized that a pathologic overactivity of mesolimbic and mesoco rtical dopamine neural systems, that mediates positive psychotic sympt oms in the acute phase of the illness, persists in some outpatients wh o are vulnerable to relapse despite appearing clinically stable. To te st and determine if putative measures of central nervous system dopami ne activity predict outcome, 41 stable outpatients receiving neurolept ic maintenance treatment underwent provocative tests with methylphenid ate in a randomized double-blind placebo controlled design in which be havioral, neuromotor, biochemical, and cardiovascular responses were m easured. Patients were then withdrawn from medication and monitored fo r 52 weeks, or until relapse. The results indicate that psychotic symp toms and their activation by methylphenidate, and the presence of tard ive dyskinesia are associated with each other and with a higher risk o f relapse. These findings partially support our hypothesis and offer p otentially useful measures for the identification of candidates for re duced dose neuroleptic maintenance treatment strategies in schizophren ia.