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In Brief: Fighting fear with a stress hormone

In Brief

Fighting fear with a stress hormone

Swiss researchers have found that artificially raising levels of the stress hormone cortisol, which is normally released by the adrenal glands in frightening situations, can paradoxically relieve performance anxiety and phobias.

In one experiment, 20 people with severe performance anxiety (social phobia) were divided into two groups that took a dose of either cortisone (which the body transforms into cortisol) or a placebo. An hour later they were surprised with a request to give a speech and do mental arithmetic before an audience and while being filmed.

The subjects who took cortisone showed less anxiety while waiting to perform, during the performance, and afterward. Learning of the surprise test increased heart rates only in the group taking the placebo. And after the speech, heart rates returned to normal faster among those who took cortisone. Cortisone had no effect on overall anxiety or on people with performance anxiety who were not put to this test.

In a second experiment, patients with spider phobias were asked to view a picture of a giant exotic spider six times over a period of two weeks as an exposure treatment. Before each viewing from the second to the fifth, they took either cortisol or a placebo. In order to measure long-term change, the experimenters provided no cortisol at the first and last viewings.

When compared with the placebo, cortisol reduced fear provoked by the spider pictures, and the difference grew greater as viewing continued. It persisted even in the final session, when subjects were not taking cortisol, so there was some lasting effect. Again, cortisol did not affect anxiety in general — only the reaction to spiders.

The researchers suggest that cortisol suppresses fearful memories inspired by the object of a phobia. It has been shown that low doses of cortisone can help prevent the retrieval of emotionally intense and traumatic memories in both human beings and animals. The effect is associated with reduced activity in the brain's medial temporal lobe, a region that becomes excited in the presence of a phobic stimulus. Cognitive behavioral therapy for phobias also lowers this activity. Further experiments may show whether low doses of cortisone can be used to treat phobias and traumatic stress symptoms.

Soravia LM, et al. "Glucocorticoids Reduce Phobic Fear in Humans," Proceedings of the National Academy of Sciences (April 4, 2006): Vol. 103, No. 14, pp. 5585–90.

Last updated:	September 05, 2008