title: Slow dissolving of emotional distress contributes to hyperarousal.
abstract: The mechanisms underlying hyperarousal, the key symptom of insomnia, have remained elusive, hampering cause-targeted treatment. Recently, restless rapid-eye-movement (REM) sleep emerged as a robust signature of sleep in insomnia. Given the role of REM sleep in emotion regulation, we hypothesized that restless REM sleep could interfere with the overnight resolution of emotional distress, thus contributing to accumulation of arousal. Participants (n = 1,199) completed questionnaires on insomnia severity, hyperarousal, self-conscious emotional distress, and thought-like nocturnal mentation that was validated to be a specific proxy for restless REM sleep (selective fragmentation: R = 0.57, P < 0.001; eye movement density: R = 0.46, P < 0.01) in 32 polysomnographically assessed participants. The experience of distress lasting overnight increased with insomnia severity (β = 0.29, P < 10(-23)), whereas short-lasting distress did not (β = -0.02, P = 0.41). Insomnia severity was associated with hyperarousal (β = 0.47, P < 10(-63)) and with the thought-like nocturnal mentation that is specifically associated with restless REM sleep (β = 0.31, P < 10(-26)). Structural equation modeling showed that 62.4% of the association between these key characteristics of insomnia was mediated specifically by reduced overnight resolution of emotional distress. The model outperformed all alternative mediation pathways. The findings suggest that restless REM sleep reflects a process that interferes with the overnight resolution of distress. Its accumulation may promote the development of chronic hyperarousal, giving clinical relevance to the role of REM sleep in emotion regulation in insomnia, depression, and posttraumatic stress disorder.
authors: Department of Sleep and Cognition, Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, 1105 BA, Amsterdam, The Netherlands; r.wassing@nin.knaw.nl.
authors: Rick
authors: R
authors: Wassing
authors: Department of Sleep and Cognition, Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, 1105 BA, Amsterdam, The Netherlands; Department of Social, Health and Organizational Psychology, Experimental Psychology Section, Utrecht University, 3584 CS, Utrecht, The Netherlands;
authors: Jeroen S
authors: JS
authors: Benjamins
authors: Department of Sleep and Cognition, Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, 1105 BA, Amsterdam, The Netherlands;
authors: Kim
authors: K
authors: Dekker
authors: Department of Sleep and Cognition, Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, 1105 BA, Amsterdam, The Netherlands;
authors: Sarah
authors: S
authors: Moens
authors: Department of Clinical Psychology and Psychophysiology, University Medical Center Freiburg, 79104 Freiburg, Germany;
authors: Kai
authors: K
authors: Spiegelhalder
authors: Department of Clinical Psychology and Psychophysiology, University Medical Center Freiburg, 79104 Freiburg, Germany;
authors: Bernd
authors: http://orcid.org/0000-0002-9436-1258
authors: B
authors: Feige
authors: Department of Clinical Psychology and Psychophysiology, University Medical Center Freiburg, 79104 Freiburg, Germany;
authors: Dieter
authors: D
authors: Riemann
authors: Department of Clinical Genetics, Complex Trait Genetics Section, Vrije Universiteit Medical Center, 1081 HV, Amsterdam, The Netherlands;
authors: Sophie
authors: S
authors: van der Sluis
authors: Department of Anatomy and Neurosciences, Vrije Universiteit Medical Center, 1007 MB, Amsterdam, The Netherlands;
authors: Ysbrand D
authors: YD
authors: Van Der Werf
authors: Department of Psychology, University of Amsterdam, 1021 WX, Amsterdam, The Netherlands;
authors: Lucia M
authors: LM
authors: Talamini
authors: Department of Psychology, University of California, Berkeley, CA 94720-1650;
authors: Matthew P
authors: MP
authors: Walker
authors: Institute for Psychotherapy, 1076 AP, Amsterdam, The Netherlands;
authors: Frans
authors: F
authors: Schalkwijk
authors: Department of Sleep and Cognition, Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, 1105 BA, Amsterdam, The Netherlands; Department of Medical Psychology, Vrije Universiteit Medical Center, 1081 HZ, Amsterdam, The Netherlands; Department of Integrative Neurophysiology, Neuroscience Campus, Vrije Universiteit, 1081 HV, Amsterdam, The Netherlands.
authors: Eus J W
authors: EJ
authors: Van Someren
mesh_terms: D000328:Adult; D000368:Aged; D004644:Emotions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D007319:Sleep Initiation and Maintenance Disorders / Q000503:physiopathology; D013315:Stress, Psychological
keywords: REM sleep; hyperarousal; insomnia; self-conscious emotion; shame