title: Dyskinesia and parkinsonism in antipsychotic-naive patients with schizophrenia, first-degree relatives and healthy controls: a meta-analysis.
abstract: BACKGROUND
  Several studies have reported the presence of dyskinesia and parkinsonism in antipsychotic-naive patients with schizophrenia as well as in their first-degree relatives. These movement disorders may therefore form an integral part of the illness and its (genetic) liability.
  
  
  METHODS
  A systematic search was conducted in the Medline, EMBASE, and PsychINFO databases to identify studies reporting on dyskinesia and parkinsonism assessed in antipsychotic-naive patients with schizophrenia (n = 213) and controls (n = 242) and separately in nonill first-degree relatives (n = 395) and controls (n = 379). Effect sizes were pooled using random-effect models to calculate odds ratios (ORs) to compare the risk of these movement disorders among patients and healthy relatives each with matched controls.
  
  
  RESULTS
  Antipsychotic-naive schizophrenia was found to be strongly associated with dyskinesia (OR: 3.59, 95% confidence interval [CI]: 1.53-8.41) and parkinsonism (OR: 5.32, 95% CI: 1.75-16.23) compared with controls. Dyskinesia and parkinsonism were also significantly more prevalent in healthy first-degree relatives of patients with schizophrenia as compared with healthy controls (OR: 1.38, 95% CI: 1.06-1.81, and OR: 1.37, 95% CI: 1.05-1.79, respectively).
  
  
  CONCLUSIONS
  The results suggest that movement disorders, and by inference abnormalities in the nigrostriatal pathway, are not only associated with schizophrenia itself but may also be related to the (genetic) risk of developing the disease.
authors.affiliation: Psychiatric Center, Symfora groep, Amersfoort, The Netherlands. jpf.koning@symfora.nl
authors.forename: Jeroen P F
authors.initials: JP
authors.lastname: Koning
authors.forename: Diederik E
authors.initials: DE
authors.lastname: Tenback
authors.forename: Jim
authors.initials: J
authors.lastname: van Os
authors.forename: André
authors.initials: A
authors.lastname: Aleman
authors.forename: René S
authors.initials: RS
authors.lastname: Kahn
authors.forename: Peter N
authors.initials: PN
authors.lastname: van Harten
mesh_terms: D015897:Comorbidity; D003342:Corpus Striatum / Q000503:physiopathology; D020820:Dyskinesias / Q000453:epidemiology* / Q000235:genetics* / Q000503:physiopathology; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D009434:Neural Pathways / Q000503:physiopathology; D016017:Odds Ratio; D020734:Parkinsonian Disorders / Q000453:epidemiology* / Q000235:genetics* / Q000503:physiopathology; D012016:Reference Values; D012306:Risk; D012559:Schizophrenia / Q000453:epidemiology* / Q000235:genetics* / Q000503:physiopathology; D013378:Substantia Nigra / Q000503:physiopathology