What is dementia, and how do you assess it? Definitions, diagnostic criteria and assessment

While many of the dening characteristics of the dementia concept have been recognized for over 100 years, developments in recent decades have both inuenced, and been inuenced by, the way we think about dementia. e discovery of biomarkers and the development of individual criteria for aetiologies like Alzheimer’s disease (AD) (Dubois et al., 2007), frontotemporal dementia (FTD) (Rascovsky et al., 2011) and dementia with Lewy bodies (DLB) (McKeith et al., 2005) have sought to rene the diagnosis, but they also present pressures on clinicians to go beyond dementia to its causal subtypes. ere are also additional challenges from an ageing population, the emergence of mild cognitive impairment (MCI) as a diagnostic entity and its relationship to ageing-related change, and wider social, political and economic pressures.