Dementia in the Ancient Greco-Roman World Was Minimally Mentioned

Demographic gaps

A challenge to this analysis is the lack of reliable demographic data for ancient Greece and Rome. Lucian’s On Long Lived Men describes reputed ages of elite Archaic and Classical age Greeks, who were politically, militarily, and intellectually active in extreme old age. While Greeks kept birth year records for many elite males, there was no birth record for women and the lower classes. Nonetheless demographic models used by current historians of ancient Greek and Roman populations [21] closely approximate the demographics of pre-industrial Sweden in 1750 [22, 23] and the modern Tsimane [24], where accidents and infections were the main cause of mortality, as prevailed in the ancient world. The Tsimane Health and Life History Project (THLHP) has assessed health and lifestyles since 2002 [25]; co-author Finch joined this project in 2012. Individual Tsimane lifespans are based on birth records and corroboration of self-statements by kin interviews [24]. Both populations shared high mortality from infections and shortened life expectancy of adults relative to the modern, which support use of Tsimane data as comparanda with ancient and other pre-industrial populations. For Tsimane [24, 25], like Sweden 1750 [22, 23], the high mortality of childhood declined by age 20 to a lower young adult mortality, followed by exponential increased mortality rates by age 40, as in modern populations. The modal age at death was about 72 years for Tsimane, like other premodern populations versus 85 years for the US [24]. While <10% survived to age 80, one-fourth still lived to become grandparents.

Ancient Greece

The city-states of Sparta and Athens required the registration of citizen children shortly after birth [26, 27]. These records gave official age thresholds for public duties: age 18, military service; 30, holding administrative office; 60 for termination of military duty. In Sparta, age 60 was also the threshold for election to the Gerousia or governing council, whose twenty-eight members served for life after election. While Greeks were fully aware of cognitive declines with age, elite elderly were valued for their civic wisdom. Even so, Greek society considered youth and not old age as the prime of life [28]. This age bias was already present in the early 7th Century BCE Homeric Odyssey, which portrayed the old as bent with age, weak, and vulnerable. Solon, the 6th Century BCE Athenian reformer, wrote about both sides of aging.

“As I age, I constantly learn many things” [29].

Contrarily “on reaching old age, speech and thought weakened” [30].

Solon is credited with a law that included old age as grounds for a son to sue his father for incompetence in managing family property [31–33].

The 4th century BCE Hippocratic text Aphorisms [34], listed ailments of the elderly that included urinary, digestive, and physical disorders; dizziness and insomnia; and deafness and blindness. We could not find any mention of memory loss in elderly in this major body of ancient medical writing, which was continued by unnamed ‘Hippocratic scholars’ for at least a century after Hippocrates died in the early fourth century BCE, allegedly in his 90s.

Aristotle, also 4th Century BCE, described cognitive aging [35].

Here, Aristotle was illustrating arguments for use by orators to prejudice juries against aged opponents, that represent the Athenian 4th Century BCE stereotype of the elderly. This passage did not include severe memory loss as an aging characteristic, consistent with the two other 4th BCE citations. In the 2nd CE, the grammarian Pollux discussed examples from 4th BCE Greek writing to illustrate proper usage [36]; he included slurred speech among characteristics of the elderly but did not mention memory loss. Similarly, Aristotle’s colleague Theophrastus [37] identifies difficulty in learning new things as typical of old age, but again did not include memory loss. We found one comment by Aristotle that extreme memory loss was a special occurrence, when elderly individuals were near death:

The duration of premorbid collapse of body and mind must have been much shorter than the prolonged agonal phase enabled by modern medical technology.

These few references suggest that ancient Greeks recognized that aging commonly brought memory issues we would recognize as MCI. The cognitive losses as described may approach early- or mid-stage AD, but not chronic progressive ADRD-like symptoms with major loss of memory loss, speech, and reasoning. We then encounter a remarkable gap in medical descriptions of old age from ancient Greece to the later Romans.

Ancient Rome

Centuries after Aristotle, in the Roman Era, we found four statements of severe memory loss, suggesting the gradual emergence of more advanced dementia. Baseline age expectations for elite Roman men resembled the prior Greek elites. The Roman requirement for military service ended at age 46; health permitting, former officers were expected to continue political and administrative activity into later ages. Mental decline was recognized but was considered exceptional. As Cicero noted in De Senectute (44 BCE) and the earliest surviving book on this topic, but extreme memory loss was not generally expected:

Equally important, Cicero did not include it as one of the four evils ascribed to old age: the end of an active life, physical weakness, the cessation of pleasures, and nearness to death. Apparently, severe memory loss among the elderly was still considered unusual. The first probable advanced case of AD or ADRD comes from Pliny the Elder (died 79 CE), who noted that the senator and famous orator, Valerius Messalla Corvinus, forgot his own name [39].

In the next century, severe memory loss became more noted. The satirist Juvenal included it among the stereotypical evils of old age [40, 41]:

Juvenal’s characterization of ARDA-like memory loss as “dementia”, means literally “out of mindedness”, and is innovative for that reason. Dementia was then a rare general term primarily used in Roman law for various mental impairments, mild to severe, that prevented elderly individuals from responsibly fulfilling their duties as family head [39]. Juvenal’s use of dementia to describe severe elderly memory loss thus suggests greater awareness of that condition among elite Roman in his time.

Later in the 2nd century CE, the Greek physician Galen [42] noted that some of the survivors of both the Antonine Plague (164–165 CE) and the 5th BCE Athenian Plague did not recognize themselves or their friends [43]:

While also one sees some who, owing to extreme age, are overcome by very similar symptoms.

Galen was personal physician to the Roman emperor, Marcus Aurelius, and an eyewitness of the Antonine Plague, possibly the first smallpox pandemic recorded in Europe [44]. Three points are notable in Galen’s account. First, Galen’s reference to dementia in the elderly is incidental to his account of mental problems he observed among victims of the Antonine Plague, AD165–180 and in the earlier Athenian plague, 5th century BCE. Second, these symptoms do not afflict all elderly individuals. Third, they are not characteristic of old age per se, but only of some in extreme old age. In Galen’s schema, extreme old age begins at age 80, when some elderly begin to have difficulty learning new things, also noted in On Hygiene [45], with the first discussion early life factors in later life health. However, this book but did not mention cognitive decline [46]. Nor was cognitive decline included in Galen’s extended list of elderly afflictions [47].

Another indication that Galen’s high age for the onset of mental decline was typical for that time is found in a century later in Censorinus’ encyclopedia of general knowledge, De Diei Natali [48], CE 238. In summarizing the current medical and philosophical views on old age, Censorinus set the age of the onset of memory loss at age 84, later than Galen.

Taken together, these four Roman Era statements suggest the emergence of greater awareness of cognitive loss of memory at advanced ages that would plausibly qualify in modern terms as clinical dementia than had been the case previously. Lacking demographic data, we cannot know if this was because more Romans survived to advanced years than earlier Greeks or not. The modern Tsimane, however, give a calibration for ancient cognitive decline.

Tsimane as a model for ancient aging

The Tsimane Amerindians have attracted attention for diseases of aging because of their minimal cardiovascular disease [49] and dementia [5, 6]. Brain imaging by high-resolution CT showed 30% slower age-related atrophy of cerebral cortex than two population samples from modern economies [50]. Cognition was assessed for 632 individuals ≥60 years from 100 villages by consensus of clinical psychologists and neurologists from the University of Southern California and showed strong evidence of increasing impairment after age 60 [5]. Those with dementia had greater prevalence of APOE E4/E4 carriers; the E4 allele is at upper normative range of 32% [51]. Postmortem brains are not available for histopathological confirmation. Overall, dementia in Tsimane aged ≥60 is 1.2% (crude prevalence), less than one-fifth of the US (8%) or Europe (6.2%) [1, 2]. All dementia cases were ≥80 years and were considered mild. This low dementia rate is also consistent with Tsimane slower cerebral cortex atrophy [50].

Moreover, Tsimane are in the lower range of other indigenous groups: rural India, 1.36% [52] and Nigerian Yoruba, 2.29% [53]. Others are higher: Cree in North America, 4% [54], Chamoros in Guam,12.2% [55], and Australian Aboriginal, 13.4% [56]. Notably, all identified Tsimane dementia cases were mild, and at least age 80 when assessed. In contrast, MCI emerged by age 60, at rates comparable to the US [5]. For Tsimane aged 60, MCI was diagnosed in 8% (35/435). Of those 35 cases, 5 mainly had impaired memory; the majority had impaired executive functions or were impaired in multiple cognitive domains. Movement symptoms included bradykinesia and rigidity that were 50% more common than cognitive impairments. Adult Tsimane are aware that hazards of older age sometimes included cognitive disabilities, but were mainly concerned with spinal pain, arthritis, and sarcopenia, like the ancients. The low Tsimane dementia prevalence and slow brain atrophy may be benefits from their demanding lifestyle of high physical activity for subsistence farming and foraging. Their minimal obesity, low HbA1c, low cholesterol, and low systolic blood pressure comprise low risk factors or cardiovascular disease (CVD) and AD in modern populations. Their high load of parasites and frequent infections may also favor minimal obesity and lower CVD [57].