title: Changes in negative symptoms and the risk of tardive dyskinesia: a longitudinal study. UK700 Group.
abstract: OBJECTIVE
  To examine whether the development of tardive dyskinesia (TD) is accompanied by a parallel process of worsening negative symptoms in a longitudinal study.
  
  
  METHODS
  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: 1.00-4.74), 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: 1.17-4.72) 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 = 1.46, 95% CI: 1.07-2.00).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Psychiatry and Neuropsychology, Maastricht University, European Graduate School of Neuroscience, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: van Os
authors.forename: E
authors.initials: E
authors.lastname: Walsh
authors.forename: E
authors.initials: E
authors.lastname: van Horn
authors.forename: T
authors.initials: T
authors.lastname: Tattan
authors.forename: R
authors.initials: R
authors.lastname: Bale
authors.forename: S G
authors.initials: SG
authors.lastname: Thompson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000009:adverse effects; D003430:Cross-Sectional Studies; D004409:Dyskinesia, Drug-Induced / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000188:drug therapy / Q000523:psychology; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D014150:Antipsychotic Agents