4. Risk factors

Would everyone get dementia if we lived long enough? ‘Risk factors’ focuses on the genetic, environmental, and physiological factors that makes dementia more or less likely to affect us. The media often distorts scientific findings with false correlations. We must be aware of these ourselves, particularly in relation to cause and effect; a factor that we may see as a cause of dementia might be a symptom. Risk factors include age, overall poor physical and mental health, blood sugar, blood and brain function, inflammation, and not using the brain. Many of these can be modified, even the effects of ageing, but there is no single cause or one-size-fits-all solution.

3. Beyond amyloid

‘Beyond amyloid’ outlines recent challenges to the amyloid cascade hypothesis of Alzheimer’s disease. This theory’s enduring popularity has not been matched by success in the clinic. Some people without dementia appear to have high amyloid levels and some brain-injured patients with more amyloid have better outcomes than those with less. One possible explanation is that neurodegeneration begins long before symptoms appear. Other theories include amyloid as the defence rather than cause, and the idea of an immune response to infection causing inflammation in the brain. All this points towards the importance of method and the acknowledgement of the roles played by other parts of the body and lifestyle factors.

5. Diagnosis and treatment

‘Diagnosis and treatment’ explains the systems used to classify brain disorders, and the change in our understanding of dementia from seeing it as threshold to a spectrum of symptoms that gradually worsen. There are five main types of dementia: Alzheimer’s, vascular dementia, frontotemporal lobar degeneration, Lewy body disease, and mixed dementia. Neurological disorders also arise from brain trauma, prion disease, substance abuse, Huntington’s disease, Parkinson’s disease, and other conditions. Timely diagnosis is critical to giving patients and their families a sense of agency and, in some cases, the ability to improve symptoms through pharmacological and non-pharmacological means. The most effective treatments are tailored to the individual.

2. What causes dementia?

‘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.

6. The future of dementia

There is still no cure for dementia, but that could change; scientists now have more tools for understanding neurodegeneration, and funding for research is at unprecedented levels. ‘The future of dementia’ explores the challenges facing sufferers and their families, including the lack of a cure or treatment based on the amyloid hypothesis, and economic and psychological demands on carers in an overstretched system dependent on unpaid labour. Our recent history of modern conveniences—cheap food, pollution, and climate change—may create more dementia patients. Making small changes in our lives can reduce our own risk of dementia and help us make life easier for those who already have it.

1. The challenges of dementia

While cognitive problems have long been associated with ageing, dementia is a relatively new concept. ‘The challenge of dementia’ shows how our understanding of it was shaped by research in the late 19th and early 20th centuries. Dementia often first appears as short-term memory failure, but symptoms vary depending on the type and the regions of the brain affected. The hippocampus is often implicated, as are synaptic failures that lead to cell death. Despite a rapidly ageing population, dementia research is underfunded. Research presents challenges for scientists, including obtaining brain samples and addressing the complex processes of neurodegeneration. Dementia does not just affect the elderly.