Department of Geriatric Psychiatry;
University Psychiatric Center KU Leuven;
Leuven 3000;
Belgium;
Center for Neuropsychiatry;
Research Group Psychiatry;
Department of Neurosciences;
Leuven Brain Institute;
KU Leuven;
Leuven 3000;
Belgium;
Alzheimer’s disease; Mild cognitive impairment; Sleep; Non-rapid eye movement sleep; Amyloid beta-peptides; Tau proteins; Electroencephalography;