We cannot do without it, and so our bodies will go to great lengths to maintain it—even to the point of long-term wear and tear if stresses do not abate. Such strain on our body’s regulatory mechanisms, which McEwen dubs “allostatic load,” leads to an excessive and prolonged release of the stress hormones adrenaline and cortisol, nervous tension, immune dysfunction, and, in many cases, exhaustion of the stress apparatus itself. We now know that the infrastructure
