Presbyophrenia: the rise and fall of a concept.

The history of the concept of presbyophrenia is traced from its inception in 1863 to the present day. Early in the twentieth century it was used to refer to a subtype of dementia characterized by confabulations, marked memory impairment, hyperactivity, disorientation, elevated mood and preserved social graces. At the time it was considered to be either a form of Korsakoff's psychosis or a subtype of senile dementia. The decline of the concept started in the 1920s and was precipitated by the redefinition of dementia in terms of impaired cognition, cortical symptomatology and specific neuropathological changes. Three explanations for the curious combination of symptoms characterizing presbyophrenia were then suggested: toxic-delirious states, manic illness in late life, or a combination of cerebrovascular disease and senile dementia. It is suggested that the dismissal of presbyophrenia could have been premature as it may capture a behavioural phenocopy of relevance to clinical practice.