Increased Risk of Parkinson's Disease in Patients With Schizophrenia Spectrum Disorders

Background PD comorbid with schizophrenia has been considered rare because these diseases associate opposite alterations in the brain dopamine system. The objective of this study was to investigate risk after a diagnosis spectrum disorder. Methods Regionally, retrospective record-based case–control study. cohort included 3045 patients treated 2004–2019 southwestern Finland. Nationally nested using registers examine Finnish who received clinically confirmed 1996–2015 (n = 22,189). previously diagnosed disorder (separate analysis for schizophrenia) were included. Comparable non-PD control groups derived from both data sets. All diagnoses based on individual clinical examinations by certified neurologists. Results In patients, prevalence earlier 0.76% regional and 1.50% nationwide data. age-matched controls, national 0.16% 1.31%, respectively. odds ratio 4.63 (95% CI, 1.76–12.19; P < 0.01) 1.17 1.04–1.31; Conclusions Schizophrenia increases later life. This association observed patient register Therefore, despite dopaminergic disease mechanisms, rather than decreases PD. increased could be related risk-altering effects receptor antagonists or vulnerability system induced illness phase-dependent dysregulation schizophrenia/schizophrenia © 2021 Authors. Movement Disorders published Wiley Periodicals LLC behalf International Parkinson Disorder Society.