d-Cycloserine Augmentation of Cognitive Behavioral Therapy for Anxiety Disorders: an Update

Although cognitive behavioral therapy (CBT) is a generally effective treatment for treating anxiety disorders, there is clearly still room for further improvements. Recent advances in neuroscience of extinction learning led to novel clinical strategies to augment exposure-based treatments with d-cycloserine (DCS), a partial agonist at the glycine recognition site of the glutamatergic N-methyl-d-aspartate receptor. This review provides an update on the current knowledge of DCS as an augmentation strategy of CBT for anxiety disorders. The adequacy of the CBT to be augmented, the dose of DCS, and the timing and duration of augmentation efforts all appear to be important moderating variables. Moreover, there is evidence that DCS may also augment fear memory reconsolidation if the fear level remains high after the exposure. Future studies need to examine whether DCS can augment CBT when administered after exposure in order to develop a tailored administration strategy to maximize its clinical utility.