Tardive dyskinesia: a role for the endogenous opioid system

Neuroleptic-induced tardive dyskinesia represents a major serious side-effect of chronic therapy with neuroleptic drugs. The pathomechanisms underlying this disorder are not well understood. Although the dopaminergic supersensitivity theory has gained most attention, there is evidence to suggest involvement of other transmitter systems. In this paper I shall discuss the possibility that the endogenous opioid system may be involved in the pathophysiology of tardive dyskinesia.