Role of Inhibition in Exposure Therapy

Abstract

While many researchers have largely focused on principles of systematic desensitization and habituation in explaining fear extinction, these processes have mixed evidence at best. In particular, these models do not account for spontaneous recovery or reinstatement of fear, nor do they explain the context dependency of extinction or rapid reacquisition. This may in part account for the significant number of patients who fail to respond to our available treatments which rely on these principles in designing exposure sessions. However, recent research is converging to suggest that an inhibitory model of fear reduction, in which the original feared association (CS-US) remains but is inhibited by a newly formed association (CS-noUS) representing safety, holds promise in explaining the long-term attenuation of fear and anxiety. This paper reviews research in a number of areas, including neuroimaging, psychophysiology, and psychopharmacology that all provide support for the inhibition model of anxiety. Limitations to this body of research are discussed, along with recommendations for future research and suggestions for improving exposure therapy for fear and anxiety disorders. Clinical implications discussed in this paper include incorporating random and variable practice in exposure sessions, multiple contexts, and pharmacological aides, among others.