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Tardive Dyskinesia and the 3-Year Course of Schizophrenia: Results From a Large, Prospective, Naturalistic Study
Objective: The objective of this study was to compare the 3-year course of schizophrenia between persons with tardive dyskinesia (TD) and persons without TD on multiple outcome measures.
Method: Data were drawn from a large, prospective, naturalistic study of persons treated for schizophrenia-spectrum disorders (DSM-IV criteria) in the United States, conducted between July 1997 and September 2003. Treatment outcomes were assessed at enrollment and at 12, 24, and 36 months postenrollment using measures of symptoms, functioning, productivity, activity, and quality of life. Participants who had TD at enrollment (fulfilling Schooler-Kane criteria, N = 637) were compared with those who did not (N = 1538) on clinical and functional measures at enrollment and across the 3 years of follow-up. Additional analyses examined those with persistent TD compared to those without persistent TD.
Results: With adjustment for known correlates of TD, participants with TD compared to those without TD had significantly more severe psychopathology, were less likely to experience symptom remission, had more severe extrapyramidal side effects, and had lower levels of quality of life and functioning, lower productivity, and fewer activities (all p < .001) across the 3-year follow-up. Findings were essentially unchanged when the subgroup of participants with persistent TD (at enrollment and at 1 year) was examined.
Conclusion: These results indicate that, in the long-term treatment of schizophrenia, persons with TD have a significantly more severe and more refractory course of illness than those without TD, suggesting poorer prognosis and the need for specialized interventions.