1. Department of Neurology; Academic Medical Center Amsterdam; The Netherlands
2. Department of Neurological Sciences, Section of Parkinson Disease and Movement Disorders; Rush University Medical Center; Chicago Illinois USA
3. New Zealand Brain Research Institute, Brain Research New Zealand - Rangahau Roro Aotearoa; Christchurch New Zealand
4. Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J Safra Program in Parkinson's disease, Toronto Western Hospital; University of Toronto; Toronto Ontario Canada
5. Arizona Parkinson's Disease Consortium, Mayo Clinic Arizona, Scottsdale, Arizona, USA and Banner Sun Health Research Institute; Sun City Arizona USA
6. Department of Medicine, Faculty of Medicine, IDIBAPS; University of Barcelona; Barcelona Spain
7. The Norwegian Centre for Movement Disorders, Department of Neurology, and Memory Clinic; Stavanger University Hospital; Stavanger Norway
8. Paracelsus-Elena-Klinik, Kassel, Germany, and University Medical Center Goettingen, Department of Neurology; Goettingen Germany
9. VA Puget Sound Health Care System and Department of Neurology; University of Washington School of Medicine; Seattle Washington USA
10. Department of Neurology; Penn State Hershey Medical Center; Hershey Pennsylvania USA
11. Brain & Mind Centre; The University of Sydney; Sydney Australia
12. Department of Neurology, National Taiwan University Hospital, College of Medicine; National Taiwan University; Taipei Taiwan
13. Department of Medical Psychology, section Medical Neuropsychology; VU University Medical Center; Amsterdam The Netherlands
14. Department of Neurology; Hospital Donostia, Donostia, San Sebastian and Ikerbasque, Basque Foundation for Science; Bilbao Spain
15. Fifth Local Sanitary Unit, Hospital Psychology, Pisa, Italy and Department of Surgical, Medical, Molecular, and Critical Area Pathology, Pisa University School of Medicine; Pisa Italy
16. Center for Neurodegenerative Diseases (CEMAND) Neuroscience Section, Department of Medicine University of Salerno; Salerno Italy
17. San Camillo Hospital IRCCS; Venice Italy
18. Department of Medical Psychology; Academic Medical Center; Amsterdam The Netherlands
19. Department of Psychology; University of Amsterdam; The Netherlands
20. Department of Clinical Neuropsychology and Center for Neuromodulation; Barrow Neurological Institute; Phoenix Arizona USA
21. Institute of Neuroscience; Newcastle University; Newcastle upon Tyne UK
22. Department of Neurosciences University of California San Diego, Parkinson and Other Movement Disorders Center; San Diego California USA
23. Department of Psychiatry; University of California San Diego, and VA San Diego Healthcare System; San Diego California USA
24. Departments of Psychiatry and Neurology; University of Pennsylvania School of Medicine, and Parkinson's Disease and Mental Illness Research, Philadelphia Veterans Affairs Medical Center; Philadelphia Pennsylvania USA