Imbalance of approach and avoidance: the yin and yang of anxiety disorders.

摘要

Two interesting articles from Harvard University investigators in this issue of Biological Psychiatry challenge us to reconsider and rethink the complexities of the underlying neurobiology of posttraumatic stress disorder (PTSD). We refer to these articles with a view to highlighting their unique contributions to the literature and the new directions they motivate for translational research in PTSD and other anxiety disorders. Milad and colleagues (1) used an operant conditioning paradigm to show that patients with PTSD have deficient extinction retention relative to trauma-exposed control subjects who had not developed PTSD. They further demonstrate, using functional MRI (fMRI), that this reduced extinction retention is related to less activation in the hippocampus and bilateral ventromedial prefrontal cortex in patients with PTSD. This article underscores our growing appreciation that PTSD is characterized by dysfunction of "unlearning" within fear circuitry, and the findings should motivate clinical research to enhance extinction retention through pharmacologic and other means. Such approaches, in parallel with those aimed at the disruption of the consolidation of fear memories, are among the most promising translational leads for PTSD therapeutics (2).