Changes in negative symptoms and the risk of tardive dyskinesia: a longitudinal study

Van Os J, Walsh E, van Horn E, Tattan T, Bale R, Thompson SG, on behalf of the UK700 Group. Changes in negative symptoms and the risk of tardive dyskinesia: a longitudinal study Acta Psychiatr Scand 2000: 101: 300–306. © Munksgaard 2000. Objective: To examine whether the development of tardive dyskinesia (TD) is accompanied by a parallel process of worsening negative symptoms in a longitudinal study. Method: A sample of 708 psychotic patients were followed over a period of 2 years, using the Abnormal Involuntary Movement Scale and the Scale for the Assessment of Negative Symptoms (SANS). Results: Of 361 individuals with no prior evidence of dyskinesia, 46 (13%) developed TD by year 2. Independent of the effects of male sex (odds ratio (OR) = 2.18, 95% confidence interval: 1.004.74), age (OR per quartile group = 1.39, 95% CI: 1.01–1.90), duration of exposure to antipsychotic medication (OR = 2.35 per 8 months, 95% CI: 1.174.72) and average SANS score (OR per quartile group = 1.38, 95% CI: 0.99–1.93), worsening of negative symptoms over the 2 previous years was asSociated with TD onset (OR per quartile group = -l.46, 95% CI: 1.07–2.00). Conclusion: The development of TD is linked, independent of the effect of antipsychotics and older age, to an illness-related pathological process, characterized by worsening negative symptoms.