MAPT and Brain atrophy: Seventeen studies (89.5%) evaluated the associations of Aβ with NPS (7 cross-sectional, 9 longitudinal, and 1 mixed), 5 (26.3%) evaluated the associations of tau with NPS (3 cross-sectional, and 2 longitudinal) and 7 (36.8%) evaluated the associations of neurodegeneration (brain atrophy, CSF total-tau and glucose metabolism) with NPS (3 cross-sectional and 4 longitudinal).