Tardive dyskinesia in affective disorders

Soon after the introduction of antipsychotic drugs into clinical practice, these agents were observed to be capable of producing not only acute extrap yramidal ("parkinsonian") side effects, but also later occurring abnormal i nvoluntary movements that came to be called tardive dyskinesia. Since antip sychotic drugs are used in a variety of conditions that include psychotic f eatures, studies have attempted to determine whether specific diagnostic su bgroups may experience different degrees of vulnerability to drug-induced m ovement disorders. This issue is important not only to inform clinical prac tice, but also to provide clues to pathophysiology. A number of studies sug gest that patients with affective disorders are at greater risk for develop ing tardive dyskinesia (controlling, to the extent possible, for other rele vant variables such as age, sex, length of treatment). Encouraging prelimin ary data with new antipsychotic drugs such as olanzapine suggest that the r isk of tardive dyskinesia associated with long-term antipsychotic drug use may be substantially reduced. This would go a long way toward improving the benefit-to-risk ratio of antipsychotic drug treatment, particularly in pat ients with affective disorders.