‘What causes dementia?’ looks at the mechanisms underlying dementia. Dr Aloysius Alzheimer identified two key features in the brain. These were a build-up of plaques dominated by the amyloid-beta protein and tangled or misfolded tau proteins. How do we research the causes of dementia? Options include animal studies, human samples including stem cells and organoids, and improved neuroscience technologies such as brain scans and MRIs. Some scientists argue that smaller soluble oligomers are as dangerous as amyloid plaques, some continue to support the amyloid cascade theory, and others look elsewhere for advances and a possible cure. Theories beyond the amyloid hypothesis are receiving more funding, changing the focus of research.