1. National Center of Epidemiology and CIBERNED, Carlos III Institute of Health Madrid Spain
2. Department of Basic and Clinical Neuroscience Institute of Psychiatry Psychology and Neuroscience at King's College London London UK
3. Parkinson Foundation Centre of Excellence at King's College Hospital London UK
4. Department of Psychiatry Ng Teng Fong General Hospital Singapore
5. Department of Clinical Neurosciences Royal Free Campus UCL Institute of Neurology London UK
6. Departments of Psychiatry and Neurology Perelman School of Medicine at the University of Pennsylvania Philadelphia PA USA
7. Parkinson’s Disease Research Education and Clinical Center (PADRECC) Philadelphia Veterans Affairs Medical Center Philadelphia PA USA