How stress hormones shape memories of fear and anxiety in humans.

Stress hormones influence the processing of fear, anxiety, and related memory mechanisms. For example, they modulate consolidation and retrieval processes associated with emotional episodic memory, fear and extinction learning. In this review, we summarize recent laboratory findings on the timing-dependent effects of stress on extinction learning and extinction retrieval. Furthermore, we relate these experiments to clinical intervention approaches relying on extinction processes such as exposure therapy, for which beneficial effects of the administration of the stress hormone cortisol have been observed. The modulation of extinction-based interventions differs from findings obtained with reconsolidation manipulation procedures utilizing the restabilization of retrieved (or reactivated) memories. In this case, blockade of adrenergic beta-receptors during reconsolidation of the fearful stimulus might represent a promising intervention. The substantial progress made in the understanding of the interaction of stress hormones with memory processes associated with fear and anxiety has the potential to enhance therapeutic success and prevent relapse in the long run.