Dyskinesia and Parkinsonism in Antipsychotic-Naive Patients With Schizophrenia, First-Degree Relatives and Healthy Controls: A Meta-analysis JeroenPFKoning1–3,DiederikETenback2,4,JimvanOs5,6, AndréAleman7,8,RenéS.Kahn3,4,andPeterN.vanHarten2,8

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. Method: A systematic search was conducted in the Med-line, EMBASE, and PsychINFO databases to identify studies reporting on dyskinesia and parkinsonism assessed in antipsychotic-naive patients with schizophrenia (n 5 213) and controls (n 5 242) and separately in nonill first-degree relatives (n 5 395) and controls (n 5 379). Effect sizes were pooled using random-effect models to cal-culate odds ratios (ORs) to compare the risk of these move-ment disorders among patients and healthy relatives each with matched controls. Results: Antipsychotic-naive schizophrenia was found to be strongly associated with dys-kinesia (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).Conclusion: The results suggest that movement disorders, and by infer-ence 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. Key words: spontaneous/movement disorders/ vulnerability/family/nonaffective psychosi