“Allostatic Load Is the Psychological Reason for Our Pandemic Brain Fog” reads the headline on an April 27 story by Emily Baron Cadloff for Vice. The language may seem abstruse, but Cadloff quickly translates it into plain English: “I’m doing so much less than I’m used to, and I’m so tired.” She’s far from alone during this period of isolation and anxiety.
Allostatic load diagram via ResearchGate
I’d never encountered allostatic load prior to the pandemic, and now I’m seeing it—and occasionally allostatic overload—quite a bit. It’s a highfalutin way to say “stressed out” that was coined, unsurprisingly, by a couple of academics, Bruce McEwen and Eliot Stellar. In 1993, McEwen (a neuroscientist) and Stellar (a psychologist) published a paper in the Journal of the American Medical Association that described “the hidden cost of chronic stress to the body over long time periods,” and defined allostatic load as “the cost of chronic exposure to fluctuating or heightened neural or neuroendocrine response resulting from repeated or chronic environmental challenge that an individual reacts to as being particularly stressful.”
McEwen and Stellar were building on a slightly older coinage, allostasis, which had been introduced in 1988 by Peter Sterling and Joseph Eyer of the University of Pennsylvania. Allostasis—from the Greek roots meaning “other” and “stability”—is the counterpart to homeostasis, which entered English in the 1920s. In physiology, homeostasis is the maintenance of constant conditions such as body temperature; allostasis, according to Sterling and Eyer, is a continual process of reaction and adaptation to changes in the environment. When the changes are too frequent or too severe, the load becomes lopsided.
The allo- prefix shows up in many scientific contexts, although it isn’t always clear that it means “differing from the usual.” Allopathy, for example, is conventional or orthodox medical practice; homeopathy (the practice of “curing like with like”) is the outlier, at least in the US.
In linguistics, an allophone is one of a set of possible spoken sounds (phones) used to pronounce a single phoneme. (Example: the aspirated p in pin and the unaspirated p in spin.) An allonym (“other name”) is a type of nom de plume that’s borrowed from a historical person. (Example: Alexander Hamilton, John Jay, and James Madison wrote the Federalist Papers under the allonym Publius “in honor of this Roman official for his role in setting up the Roman Republic.”)
Allo- also hides out in allergy, the English form of German allergie, which was coined in 1906 by the Austrian physician Clemens Peter Freiherr von Pirquet to describe “a heightened reaction to an antigen to which an individual has been previously exposed.” The -ergy part of the word comes from a Greek root meaning “activity,” as in “energy.”
Bruce McEwen, who coined allostatic load in 1993, died at age 81 on January 2, 2020, just before the pandemic caused his coinage to trend. McEwen’s New York Times obituary noted that “[b]y the end of his career Dr. McEwen had expanded his research to look at the impact of stress on communities, finding that chronic stress disproportionally affected marginalized people and increased their risk of illnesses.”