We searched PubMed, Scopus, Embase Ovid, PsycINFO, and CINAHL from inception to 22 May 2024 for randomised controlled trials (RCTs) and observational studies that compared the use of Ang-II stimulating (thiazides, Ang-II receptor blockers, and dihydropyridine calcium channel blockers) and inhibiting AHMs (β-blockers, angiotensin-converting enzyme inhibitors, and non-dihydropyridine calcium channel blockers) and the subsequent risk of developing dementia. Here, ACE is linked to dementia.