Neuroleptic antipsychotic drugs are used in the treatment of a variety of psychiatric conditions, including affective disorder. This chapter concerns the association between tardive dyskinesia and affective disorder, inasmuch as affective illness has been established as a risk factor in the development of tardive dyskinesia (Gardos & Casey, 1984; Casey, 1988). The evidence for this association will be reviewed, and possible mechanisms will be considered. Because the somatic treatments used for bipolar and unipolar patients may influence the development and manifestations of tardive dyskinesia, we shall briefly review the effects on tardive dyskinesia of antidepressants, electroconvulsive treatment (ECT), lithium carbonate, and anticonvulsants.

Epidemiology

The earliest relevant studies grew out of clinical observations that some tardive dyskinesia patients were experiencing concurrent depression or had been depressed in the past (Rosenbaum et al., 1977). Other studies suggested that many patients with tardive dyskinesia had been improperly diagnosed as schizophrenic and that the more appropriate psychiatric diagnosis would have been affective disorder (Davis, Berger, & Hollister, 1976; Rush, Diamond, & Alpert, 1982; Casey & Toenniessen, 1983). Several studies compared tardive dyskinesia patients with non-dyskinetic control subjects and found affective disorder to be more common in the tardive dyskinesia groups (Hamra et al., 1983b; Alpert & Rush, 1984; Wolf et al., 1985). In a recent study, Yassa et al. (1992) showed that major depression among tardive dyskinesia patients was significantly more frequent (12 of 20, or 60%) than was primary degenerative dementia (42 of 49, or 24.5%) among a cohort of psychogeriatric inpatients.