RISK OF TARDIVE-DYSKINESIA IN OLDER PATIENTS - A PROSPECTIVE LONGITUDINAL-STUDY OF 266 OUTPATIENTS

Background: Neuroleptic-induced tardive dyskinesia (TD) is a major iat rogenic disorder that is more prevalent among older patients. The obje ctive of this study was to determine the incidence of and risk factors for TD in neuroleptic-treated patients over age 45 years. Methods: We studied 266 middle-aged and elderly outpatients with a median duratio n of 21 days of total lifetime neuroleptic exposure at study entry. Mo st patients were treated throughout the study with either a high-poten cy or a low-potency neuroleptic and maintained on relatively low doses . The patients were followed up at 1- to 3-month intervals with ''blin d'' assessment of psychopathologic condition, clinically as well as in strumentally (ie, using electromechanical sensors with computerized da ta reduction, including spectral analysis) evaluated movement disorder , and global cognitive function. Results: Cumulative incidence of TD w as 26%, 52%, and 60% after 1, 2, and 3 years, respectively. The princi pal risk factors for TD were duration of prior neuroleptic use at base line, cumulative amount of high-potency neuroleptics, history of alcoh ol abuse/dependence, borderline or minimal dyskinesia, and tremor on i nstrumental assessment. Conclusion: Use of higher amounts of neurolept ics, particularly high-potency ones, should be avoided in older patien ts, patients with alcohol abuse/dependence, or patients with a subtle movement disorder at baseline; these patients are at a higher risk of developing TD.