Archival ReportSleep Deprivation Disrupts Recall of Conditioned Fear Extinction

BackgroundLearned fear is crucial in the development and maintenance of posttraumatic stress disorder and other anxiety disorders, and extinction of learned fear is necessary for response to exposure-based treatments. In humans, research suggests that disrupted sleep impairs consolidation of extinction, though no studies have examined this experimentally using total sleep deprivation.MethodsSeventy-one healthy control subjects underwent a paradigm to acquire conditioned fear to a visual cue. Twenty-four hours after fear conditioning, participants underwent extinction learning. Twenty-four hours after extinction learning, participants underwent extinction recall. Participants were randomized to three groups: 1) well-rested throughout testing (“normal sleep”; n = 21); 2) 36 hours' total sleep deprivation before extinction learning (“pre-extinction deprivation”; n = 25); or 3) 36 hours' total sleep deprivation after extinction learning and before extinction recall (“post-extinction deprivation”; n = 25). The groups were compared on blink electromyography reactivity to the condition stimulus during extinction learning and recall.ResultsThere were no differences among the three groups during extinction learning. During extinction recall, the pre-extinction deprivation group demonstrated significantly less extinction recall than the normal sleep group did. There was no significant difference between the normal sleep and post-extinction deprivation group during extinction recall. Results indicated sleep deprivation before extinction training significantly disrupts extinction recall.ConclusionsThese findings suggest that 1) sleep deprivation in the immediate aftermath of trauma could be a potential contributor to posttraumatic stress disorder development and maintenance via interference with natural extinction processes and 2) management of sleep symptoms should be considered during extinction-based therapy.