1. Lovisenberg Diaconal University College, Oslo, Norway
2. Norwegian National Advisory Unit on Ageing and Health, Tønsberg, Norway
3. Department of Neurology and Psychiatry, Neuropsychiatry Clinics, Massachusetts General Hospital, Boston, MA, USA
4. Department of Psychiatry, Neuropsychiatry Clinics, Massachusetts General Hospital, Boston, MA, USA
5. Harvard Medical School, Boston, MA, USA