INCIDENCE AND RISK-FACTORS FOR SEVERE TARDIVE-DYSKINESIA IN OLDER PATIENTS

Background Severe tardive dyskinesia (TD) represents a serious and pot entially disabling movement disorder, yet relatively little is known a bout the incidence of and risk factors for severe TD. Method We report the results of a longitudinal prospective incidence study of severe T D in 378 middle-aged and elderly neuropsychiatric patients. Psychiatri c, neuropsychological, pharmacological and motor variables were obtain ed at intake and at regular intervals for 36 months. Results The cumul ative incidence of severe TD was 2.5% after one year, 12.1% after two years, and 22.9% after three years. Individual univariable Cox regress ion analyses were conducted to identify demographic, psychiatric, moto r and pharmacological predictors of severe TD. Results indicated that higher daily doses of neuroleptics at study entry, greater cumulative amounts of prescribed neuroleptic, and greater severity of worsening n egative symptoms were predictive of severe TD. Conclusions These findi ngs suggest that conventional neuroleptics may be prescribed to older patients only when necessary and at the lowest effective dosage. Addit ional caution is recommended in patients exhibiting negative symptoms.