The first reference to an association between aging and dementia (i.e., senile dementia) was made by Aretaeus of Cappadocia in the second century. In describing the aging process, he used the term dotage to mean “a torpor of the senses and a stupefaction of the gnostic and intellectual faculties” that accompanies old age (Aretaeus 1861, p. 301). From at least this point in time, the distinction between normal brain aging and late-life brain disease has been unclear. For example, according to Folsom (1886),

Senile dementia is simply an excess of the natural weak-
ness of old age out of proportion to the bodily state, an
exaggerated childishness of senility to the extent of pro-
ducing irresponsibility… Memory fails first, and a con-
dition of general weakness of mind follows rapidly af-
terward. Secretiveness, suspicions, delusions and
hallucinations of the special senses are almost always
present. (p. 174)

He went on to say (presaging recognition of the frontotemporal dementias and their differentiation from Alzheimer disease),

It is not uncommon for the early symptoms to consist in
an inhibition of the higher faculties of the mind, so that
the lower impulses become prominent. The sense of
right and wrong and the moral perceptions may become
entirely weakened. Acts of indecency, dishonesty, injus-
tice and depravity may follow impaired judgment, and
yet so far precede strikingly perverted memory and gen-
eral intelligence as to make the insanity (e.g., mental dis-
order) which is obvious to an experienced observer, fail
entirely to impress itself on the minds of the community.
(Folsom 1886, p. 174)

Philippe Pinel, who in the late 18th century became superintendent of the Parisian psychiatric hospitals named the Bicêtre and the Salpetrière (saltpeter factory), used the term demence (i.e., dementia) to designate one of the five classes of mental derangement. Although it is described as the derangement that abolishes the thinking faculty, dementia appeared to refer to schizophrenia and other psychotic disorders formerly classified as functional psychoses (Pinel 1806/1962, p. 165). Pinel’s class of derangement that most closely corresponds to the DSM-IV-TR (American Psychiatric Association 2000) category of dementia was “idiotism, an obliteration of the intellectual facilities and affections” (Pinel 1806/1962, p. 165). Esquirol (1845/1965), Pinel’s successor at the Salpetrière, used dementia to describe mental disorders that were manifested by weakened sensibility, understanding, and will, with impaired recent memory, attention, reasoning, and abstracting ability. He described the dementias as acute, chronic, and senile, and included end-stage psychotic disorders and stuporous depression in this category. American physician Benjamin Rush (1812) used the term fatuity to designate the mental disorder characterized primarily by impaired reasoning and memory. James Prichard (1837), an English physician who did not regard dementia as a normal consequence of old age, suggested that dementia might be primary or secondary to other disorders and delineated a four-stage natural history of dementia that parallels the course of Alzheimer disease: 1) loss of recent memory with preservation of remote memory, 2) loss of reason, 3) loss of comprehension, and 4) loss of ability to care for vegetative functions.

Dementia has long had important legal implications as a type of insanity; insanity is now exclusively a legal term for a condition in which, as a result of a profound disturbance in the intellectual facilities, a person has lost more or less completely his or her free will and has ceased thereby to be responsible to society for his or her actions.

As a result of their diminished capacity to make judgments and direct their own behavior, demented persons were classed under English law as non compos mentis or lunatics (Prichard 1837, p. 254) and were held to have diminished responsibility/capacity in relation to the severity of their mental impairment. For this reason, the term insanity still persists in legal proceedings, but it was clear to many from the latter part of the 19th century that insanity was in fact the result of a brain disorder (Folsom 1886, p. 104). The first attempts to quantify dementia severity arose because of the need to quantify legal capacity.

Perhaps the earliest schema for quantifying dementia was developed by Hoffbauer (cited by Prichard 1837, pp. 256-261). It included the categories of bloedsinn (translated from the German by Prichard as “silliness”) and dumbest (translated as “stupidity”), which are roughly equivalent to executive deficit and intellectual deficit, respectively. The primary characteristic of silliness was impaired judgment, again anticipating the recognition of frontal lobe syndromes. The primary characteristic of stupidity was inability to acquire and retain information.

Stages of silliness, from most to least impaired, included 1) inability to judge new situations, 2) inability to judge familiar situations, 3) marked impairment of memory and attention, 4) clouding of consciousness, and 5) stupor and unresponsiveness. The three stages of stupidity began with the inability to weigh opposites, progressed through the inability to reason, and culminated in the inability to express ideas in language.

Emil Kraepelin (1913) distinguished the so-called functional psychoses from the consequences of obvious brain damage, calling the former the insanities and the latter varieties of imbecility. The two categories of imbecility were acquired imbecility (dementia) and congenital (ordinary) imbecility. The dementia category included apoplectic dementia due to vascular disease, old age (or senil-
ity), and epilepsy.