Exciting new evidence has shown that pharmacological agents known as “cognitive enhancers” can increase fear extinction in animals and facilitate exposure-based therapy in humans. Supported by animal evidence, clinical studies have shown that D-cycloserine (DCS), a N-methyl-D-aspartic acid (NMDA) receptor partial agonist, facilitates the retention (and maintenance when tested months later) of extinction memory from CBT in a number of anxiety disorders (Davis et al., 2006; Guastella et al., 2008; Hofmann, 2007, 2008; Ledgerwood et al., 2003, 2004, 2005; Norberg et al., 2008; Ressler et al., 2004; Walker et al., 2002). These studies demonstrate the clinical impact of translational neuroscience by coupling the basic science of fear extinction learning and human neuropsychopharmacology. However, other studies have failed to find any evidence that DCS facilitates fear extinction or exposure therapy (Guastella et al., 2007a; Guastella et al., 2007b; Norberg et al., 2008; Parnas et al., 2005; Storch et al., 2007), so while DCS is a promising cognitive enhancing agent for extinction and exposure therapy there is a need to investigate additional pharmacological targets.
