Studies // Cited work

Protective and damaging effects of stress mediators

McEwen, B. S. (1998). Protective and damaging effects of stress mediators.

Level D Review doi:10.1056/NEJM199801153380307

What this study supports

Supports the claim that stress mediators protect acutely and contribute to damage when chronically activated or poorly terminated. An influential conceptual review; the allostatic load construct remains debated in measurement.

Who was studied
Not applicable: a narrative review of stress mediators and allostatic load.
Design
Review
Level of evidence
Cross-sectional, observational, qualitative work and narrative reviews.

Claims that rest on it

Each claim states what the site asserts, at what strength, and with what caveat.

TheoreticalLevel DConfidence MODERATE

Relief changes how a state feels and resolution changes the conditions that produce it; relief has value of its own but, taken together with reinforcement, acute mood effects and memory biases, it can be repeated without the underlying difficulty changing.

Scope
The project's central argument, synthesised from separate lines of research.
Caveat
No study cited here tested the full loop directly; the argument is a synthesis and could be wrong for particular people or activities.

Last reviewed · Review due · relief-not-resolution-thesis

EmpiricalLevel DConfidence HIGH

Stress mediators such as cortisol and catecholamines are protective in the short term but contribute to allostatic load when chronically activated or poorly terminated.

Scope
Human stress physiology as summarised in a narrative review.
Caveat
Allostatic load is a construct whose measurement is still debated, and the review predates much later work.

Last reviewed · Review due · allostatic-load

TheoreticalLevel DConfidence MODERATE

Allostatic load has been described as the cumulative cost of stress responses that are activated too often or not terminated efficiently, which implies that load can build up when challenges recur faster than recovery.

Scope
A conceptual framework, illustrated with arbitrary units in the allostatic-load model.
Caveat
The measurement of allostatic load is debated, and the model's linear input and proportional recovery are simplifications with no physiological calibration.

Last reviewed · Review due · allostatic-load-accumulation-model

TheoreticalLevel DConfidence HIGH

Allostasis, a term introduced by Sterling and Eyer, describes physiological regulation that anticipates demands and changes set points rather than holding them constant; allostatic load names the cumulative cost of repeated or chronic activation.

Scope
The concepts as defined by their originators.
Caveat
The definitions are theoretical and their contrast with homeostasis is disputed.

Last reviewed · Review due · allostasis-predictive-regulation