Introduction

For the past 30 years the Western world has seen the evolution of our understanding of dementia emerge through three relatively distinct paradigm shifts or ‘moments’. In the first moment, the condition was considered a fairly predictable sign of normal ageing, and hence was largely unremarkable and invisible. For example, in 1982, one of the authors (DO) recollects reading the physician-provided medical diagnosis for an 82-year-old woman with severe cognitive impairment preparing for a move into a care home; it read ‘old woman living with old man’. What is somewhat astounding retrospectively is that throughout the discussion about the suitability of this woman to enter this care facility, no one on the sevenperson admission committee – composed of health and social care professionals including another physician – challenged this ‘diagnosis’ (although it was treated humorously). While this may represent an extreme situation, the point remains that relegating problematic cognitive deterioration of an older family member to the expectable realm of ‘senility’, or simply the ageing process, was not unusual.

The second moment arguably began to dominate by the early 1980s, when the unquestioning acceptance of deteriorating cognitive functioning as a sign of normal ageing was increasingly challenged and relabelled as a biomedical condition; in particular, the recognition that Alzheimer's disease was not simply a disease of younger adults heralded an increasingly biomedical era. This understanding of dementia as a neurodegenerative disorder, characterised by symptoms that included declining memory, insight, judgement and ability to communicate, became the dominant lens within Western culture for understanding many conditions associated with deteriorating cognition in older adults. Using the language of ‘dementia’, this lens assumes a trajectory of irrevocable decline related to neuropathological changes, and predicts that over time the person with dementia will become progressively more dependent on others for all aspects of his or her care.

The medicalisation of dementia has had important benefits. Perhaps most significantly, it has generated scientific interest and research, which has led to more refined diagnostic practices, including increased precision around earlier diagnosis and prognosis. For example, a whole new category of pre-dementia ‘diagnosis’, including cognitive impairment, no diagnosis (CIND) or mild cognitive impairment (MCI), is now based on the assumption that we have sufficient understanding of normal and abnormal brain changes to achieve earlier, accurate diagnosis.