Studies have shown that glucocorticoids impair memory retrieval in healthy subjects. In fact, the investigators could show that cortisol has a fear reducing effect in patients with post-traumatic stress disorder and in phobic patients, resulting particularly in reduced symptoms of anxiety and in reduced stress reactivity. Interestingly enough, pharmacologically induced high levels of glucocorticoids lowered the subjective feeling of anxiety and stress in situations activating per se the HPA-axis. Further it has been shown that the combined therapy of glucocorticoid administration and exposition based psychotherapy leads to better therapy outcome in patients with specific phobias.