Prospective study of tardive dyskinesia incidence in the elderly

OBJECTIVES

To investigate the incidence of tardive dyskinesia in elderly individuals beginning treatment with antipsychotic drugs and to identify risk factors for the development of tardive dyskinesia in the elderly.

DESIGN

A cohort of previously neuroleptic-naive patients was identified at the time of initiation of antipsychotic drug treatment. Patients were evaluated at baseline and followed up at 3-month intervals for periods ranging from 3 to 119 weeks.

SETTING

Subjects were recruited from the psychiatric and geriatric medical services of two medical centers, a geriatric institute, and three nursing homes in the metropolitan area of New York City, NY.

PATIENTS

Two hundred fifteen individuals older than 55 years have entered the study thus far. Preliminary data are presented for 160 patients who were followed up for at least 1 month. Their age range was 57 to 99 years (mean, 77 years). Seventy-two percent were women and 87% were white. Sixty-seven percent of patients had a diagnosis of organic mental syndrome and 42% had a psychiatric diagnosis.

INTERVENTIONS

A naturalistic, longitudinal, repeated assessment paradigm was employed. Assessments included abnormal involuntary movements, extrapyramidal signs, psychiatric symptoms, and medical and drug treatment histories.

MAIN OUTCOME MEASURE

The incidence of tardive dyskinesia was determined using a standardized rating instrument and survival analysis.

RESULTS

The incidence of neuroleptic-induced dyskinesia was 31% (95% confidence interval, 20%, 42%) after 43 weeks of cumulative neuroleptic treatment. Psychiatric (as opposed to organic) diagnosis and presence of extrapyramidal signs early in treatment were associated with increased tardive dyskinesia vulnerability.