Tardive dyskinesia has been regarded as a long-term complication of neuroleptic administration to patients with the diagnosis of schizophrenia. Of the first 14 patients evaluated for an investigation of tardive dyskinesia 9 met diagnostic criteria for depression. Neuroleptics produce blockade of post-synaptic dopaminergic receptors. Tardive dyskinesia occurs when neuroleptics are discontinued, and is regarded as a manifestation of super-sensitive post-synaptic dopaminergic receptors. Chronically decreased neurotransmission in the synapse of a patient with depression may contribute to the development of a super-sensitive receptor and could explain the high proportion of patients with depression seem in this sample of patients with tardive dyskinesia.