Late Sleep Enhances Fear Extinction Recall in Posttraumatic Stress Disorder

Abstract

Sleep disturbances are a key feature of posttraumatic stress disorder (PTSD) and is implicated in extinction (i.e., previously threatening stimuli are now safe) and safety (i.e., stimuli signalling absence of threat) memory consolidation. This study examined whether sleep early versus late sleep impacts extinction and safety recall, indexed by skin conductance response (SCR) and threat expectancy ratings, in trauma-exposed adults with and without likely PTSD. Seventy adults (M age 25.78 ±6.71 years; 32.86% with likely PTSD) completed a two-day fear conditioning paradigm. Following extinction learning, participants were assigned to sleep restricted to the first half of the night, the second h..