title: Memory suppression trades prolonged fear and sleep-dependent fear plasticity for the avoidance of current fear.
abstract: Sleep deprivation immediately following an aversive event reduces fear by preventing memory consolidation during homeostatic sleep. This suggests that acute insomnia might act prophylactically against the development of posttraumatic stress disorder (PTSD) even though it is also a possible risk factor for PTSD. We examined total sleep deprivation and memory suppression to evaluate the effects of these interventions on subsequent aversive memory formation and fear conditioning. Active suppression of aversive memory impaired retention of event memory. However, although the remembered fear was more reduced in sleep-deprived than sleep-control subjects, suppressed fear increased, and seemed to abandon the sleep-dependent plasticity of fear. Active memory suppression, which provides a psychological model for Freud's ego defense mechanism, enhances fear and casts doubt on the potential of acute insomnia as a prophylactic measure against PTSD. Our findings bring into question the role of sleep in aversive-memory consolidation in clinical PTSD pathophysiology.
authors.affiliation: Department of Adult Mental Health, National Institute of Mental Health, National Center of Neurology and Psychiatry, Japan. kenicik@ncnp.go.jp
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kuriyama
authors.forename: Motoyasu
authors.initials: M
authors.lastname: Honma
authors.forename: Takuya
authors.initials: T
authors.lastname: Yoshiike
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Kim
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001143:Arousal; D001362:Avoidance Learning; D003463:Cues; D004192:Discrimination, Psychological; D019260:Expressed Emotion; D005239:Fear / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D021641:Recognition, Psychology; D012307:Risk Factors; D012890:Sleep; D012892:Sleep Deprivation; D013313:Stress Disorders, Post-Traumatic / Q000209:etiology; D055815:Young Adult