MAPT and hippocampal atrophy: Furthermore, the observed association between tau and hippocampal atrophy in A.H.T.-users, unlike nonusers, suggests that A.H.T.s may modulate tau pathology and hippocampal atrophy via similar mechanisms; partly explaining the recent meta-analysis of more than 800 cases from Australia reporting benefit of A.H.T.’s treatment in late-mid and later life to prevent dementia (48).