Yet much remains unknown. For instance, the current research involved only a very short period of time. Though the memory appeared erased on day three, would that still be true a month later? And, it's unclear how effective will propranolol be against longer-term memories, such as traumatic childhood memories that persist into adulthood.
Besides, the experimental memories were not exactly erased in this study, Taylor noted: The propranolol-treated subjects no longer flinched in reaction to the stimulus, yet they knew that they should. That, Taylor suggested, could limit propranolol's clinical utility.
"Being afraid of something doesn't just involve a physiological response," Taylor said, "it's how you think about it and how it affects your behavior."
For more about anxiety disorders, visit the U.S. National Institute of Mental Health.SOURCES: Jane Taylor, Ph.D., professor, psychiatry, Yale University, New Haven, Conn.; Mark Bouton, Ph.D., professor, psychology, University of Vermont; Feb. 15, 2008, Nature Neuroscience, online