Pharmacological facilitation of fear extinction and the search for adjunct treatments for anxiety disorders--the case of yohimbine.
There is current interest in identifying drugs that facilitate fear extinction, as this form of learning is the basis of certain cognitive therapies for anxiety disorders. Following an initial report several years ago that the alpha2-adrenoreceptor antagonist yohimbine facilitated extinction in mice, more recent studies have shown mixed effects or even impairment. It has become clear that the effect of yohimbine on extinction depends on a number of factors, including genetic background, contextual variables and the presence of competing behaviors. To what extent theses effects of yohimbine are mediated through the alpha2-adrenoreceptor, as opposed to other sites of action, is also uncertain. More work is needed before this drug can be approved as a pharmacological adjunct for extinction-based therapies. More generally, the case of yohimbine may serve as a model for the development of other extinction facilitators.
Holmes
Andrew
A
Section on Behavioral Science and Genetics, Laboratory for Integrative Neuroscience, National Institute on Alcoholism and Alcohol Abuse, NIH, Bethesda, MD 20852, USA.
Quirk
Gregory J
GJ
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D001008:Anxiety Disorders / Q000188:drug therapy* / Q000503:physiopathology; D001522:Behavior, Animal / Q000187:drug effects; D005108:Extinction, Psychological / Q000187:drug effects; D005239:Fear / Q000187:drug effects; D006801:Humans; D051379:Mice; D018341:Receptors, Adrenergic, alpha-2 / Q000187:drug effects / Q000378:metabolism; D015016:Yohimbine / Q000494:pharmacology*
D000317:Adrenergic alpha-Antagonists; D018341:Receptors, Adrenergic, alpha-2; D015016:Yohimbine