Can a Small “Dose” of Stress Help Long-Term Reactions?

A single severe stress can trigger delayed and prolonged increases in anxiety and in amygdala activity in people and animals, along with altered levels of adrenal stress hormones (cortisol; in rodents, corticosterone). Paradoxically, clinicians have observed that patients in intensive care units who receive high adrenal steroid doses have a lower risk for developing post-traumatic stress disorder, and cortisol might help extinguish fear (JW Psychiatry May 2 2011). Researchers in India used animals to explore this paradox.

Rats subjected to immobilization stress exhibited anxiety-like behavior in an elevated maze 10 days later. Injection of an inactive liquid 30 minutes before the stress prevented this effect, although the same injection with…