The Alzheimer’s “Hockey Stick” and the History of Late Twentieth Century Biomedicine

In this post, I use Google’s Ngrams to graphically summarize the history of Alzheimer’s disease, and discuss the direction of my current research.

My research on the history of Alzheimer’s began with a very simple historical question: how and why did the unlikely eponym Alzheimer’s emerge seemingly out of nowhere in the late 1970s to very quickly become a household word in the United States – one of the most feared medical diagnoses and the object of a one of the most well-funded disease-specific campaigns for public awareness and biomedical research in American history.  As can be seen in the google ngram below, which graphs the percentage of the millions of English language books in the Google database in which the term Alzheimer’s disease appeared every year from Alzheimer’s first publication of a case in 1906 to the year 2000, Alzheimer’s disease only became widely discussed in print after 1980. Since Alzheimer’s was available as a medical category from the start of the century, how do we account for the iconic “hockey stick” shape of public awareness about Alzheimer’s, suggesting that it only became a hot issue late in the 20th century?

It is commonly argued that this simply reflects heightened awareness of the aging of the population over the past few decades, making Alzheimer’s a much more visible problem. But a second ngram below for the terms old age, aged and aging suggests that it is not so simple. Though there is an uptick around 1980, public awareness and discussion of aging has been much more stable throughout the modern period. The sudden emergence of Alzheimer’s must be linked to something more specific in American culture and society.

My explanation of the Alzheimer’s hockey stick has two parts. First, of course, was that Alzheimer’s did not really emerge out of nowhere in the late 1970s, but was in fact part of a long developing set of cultural anxieties about aging, senility and selfhood. I argued in my first book that the roots of public anxiety about age-associated cognitive deterioration in American society and culture can be found in the mid-nineteenth century emergence of industrial capitalism, which saw ongoing heated public debate about whether older workers, burdened with what medical science characterized as inevitably deteriorating bodies and brains, could possibly keep up with the pace of industrial work and complex, bureaucratic management. Through the mid-twentieth century, as consumer culture became more deeply embedded in American society, anxiety about aging gradually shifted to whether older people could create and sustain a coherent self-identity in the vacuum of retirement and endless leisure, which by the late 1940s had become as an ambivalent reality for most Americans over the age of 65. The quick and dirty summary of my argument here is that, as selfhood became a more problematic cultural category in industrial and mass consumer society. as identity became more of a project than an ascribed status in modern America, old age increasingly became a site of cultural anxiety, and senile dementia – which destroyed the ability to craft a coherent and cohesive self-narrative – became a far more frightening condition, indeed one of the most frightening of all medical conditions in post-World War II America. And this fear set the stage for the explosive emergence of Alzheimer’s after 1980.

The second part of my argument about the Alzheimer’s hockey stick concerns the way in which Alzheimer’s disease was re-constructed as a specific disease category in the mid-1970s. From the time it was created by Emil Kraepelin and Alois Alzheimer in the early twentieth century, Alzheimer’s disease has always been a troublesome construction – at once one of the most stable and one of the most ambiguous of disease categories. On the one hand, Alzheimer and Kraeplin found it an interesting and potentially important disease category because it defined one of the very few psychiatric conditions with a set of clear clinical symptoms that could be correlated with an equally clear set of pathological structures in the brain. From their work to the present, Alzheimer’s has been understood within the same basic framework of brain pathology – the neuritic plaques and neurofibrillary tangles – correlated with a clear clinical picture of global cognitive deterioration. But on the other hand, it has been difficult to disentangle Alzheimer’s disease from aging. In 1910, Kraepelin created the eponym Alzheimer’s disease based on his protégé’s description of the characteristic brain pathology and clinical symptoms of senile dementia in a patient who was only 51 years old. Kraepelin thought that early age of onset – which he arbitrarily defined as before the age of 65 – was itself enough to warrant putting such cases in a separate disease category. The basic rationale was that while dementia in older people might be thought of as an extreme variant of the common if not universal cognitive decline associated with the normal aging process, the same condition occurring at an earlier age was very unusual and so could reasonably be thought of as a disease. Thus as conceptualized by Kraepelin and Alzheimer, this condition occupied a rather marginal nosological space. As senile dementia, it was a very common condition, but was so closely associated with aging that it seemed questionable to call it a disease. As Alzheimer’s pre-senile dementia, it seemed reasonable to think of it as a disease, but one that was vanishingly rare. This distinction persisted in the medical literature for decades, though it was clearly understood that they were essentially the same condition.

The distinction was eliminated by a group of American researchers, government officials within NIH and activist caregivers who sought to generate awareness and funding for biomedical research into dementia, and who were savvy about the political ramifications of disease categorization. In the mid-1970s, through a number of prominent editorials in various medical journals and NIH sponsored consensus conferences, they successfully argued that since there was no meaningful clinical or pathological distinction between Alzheimer’s and senile dementia, the two should be considered a single entity – and that entity, crucially, should be called Alzheimer’s. By combining the two categories, they could claim that the condition was a major health problem afflicting millions of people; by calling it Alzheimer’s rather than senile dementia, they could claim it was not “just aging,” but a dread disease worthy of a massive, publicly funded research initiative to understand its cause and discover a means of effective treatment or prevention. This strategy brilliantly harnessed deep anxieties about aging to the growing power and prestige of biomedicine in the second half of the twentieth century.

All of this can be read quite nicely into the final ngram below – the terms senility and senile dementia gradually rise in prevalence in English language books from the late-nineteenth through the twentieth century – culminating in the explosion of interest in Alzheimer’s disease after 1980.

My current research will go beyond these broad political and social ramifications of the emergence of Alzheimer’s as a major public issue to explore in some detail the medical world that was actually created by it. The massive investment of financial, institutional, and intellectual capital into research on the causes of and possible treatments for Alzheimer’s disease by both the federal government and private industry since the 1970s transformed dementia research from a small field with a broad agenda, to a massive multi-faceted research enterprise focused much more narrowly on pathological mechanisms. As I’ve remained peripherally connected to the Alzheimer’s field with various projects, I’ve been most impressed with the difficulty of maintaining coherent institutional and intellectual frameworks that connect and coordinate the efforts of diverse practitioners working on different agendas within modern biomedicine. In many ways what happened in the Alzheimer’s field reflects broader changes in the scale and structure of medicine during the same time period, so understanding how these developments shaped the way that researchers in the dementia field worked, the way that physicians diagnosed and treated dementia, the way that patients and their family members experienced both dementia and the treatment and care received by medical and health care providers can help move us to a richer, more nuanced understanding of what medicine has become since the latter half of the twentieth century.