Estrogen inhibits the dopaminergic supersensitivity induced by neuroleptics.

Administration of estrogen to rats during the period of withdrawal from chronic haloperidol attenuated the characteristic increase in apomorphine-induced stereotypy and the increase in (3H) spiroperidol binding. This apparent ability of estrogen to "down-regulate" brain dopamine receptors could lead to useful pharmacological treatments of tardive dyskinesia and possibly of other hyperdopaminergic states.