title: Insomnia disorder is associated with increased amygdala reactivity to insomnia-related stimuli.
abstract: OBJECTIVE
  Alterations in emotional reactivity may play a key role in the pathophysiology of insomnia disorder (ID). However, only few supporting experimental data are currently available. We evaluated in a hypothesis-driven design whether patients with ID present altered amygdale responses to emotional stimuli related and unrelated to the experience of insomnia and, because of chronic hyperarousal, less habituation of amygdala responses.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Departments of Psychiatry and Psychotherapy and of Radiology of the University of Freiburg Medical Center.
  
  
  METHODS
  There were 22 patients with ID (15 females; 7 males; age 40.7 ± 12.6 y) and 38 healthy good sleepers (HGS, 21 females; 17 males; age 39.6 ± 8.9 y).
  
  
  METHODS
  N/A.
  
  
  RESULTS
  In a functional magnetic resonance imaging session, five different blocks of pictures with varying emotional arousal, valence, and content (insomnia-relatedness) were presented. Pictures were presented twice to test for habituation processes. Results showed that patients with ID, compared to HGS, presented heightened amygdala responses to insomnia-related stimuli. Moreover, habituation of amygdale responses was observed only in HGS, but not in patients with ID who showed a mixed pattern of amygdala responses to the second presentation of the stimuli.
  
  
  CONCLUSIONS
  The results provide evidence for an insomnia-related emotional bias in patients with ID. Cognitive behavior treatment for ID could benefit from strategies dealing with the emotional charge associated with the disorder. Further studies should clarify the role of ID with respect to habituation of amygdala responses.
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Germany.
authors.forename: Chiara
authors.initials: C
authors.lastname: Baglioni
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Germany: Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Spiegelhalder
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Germany.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Regen
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Feige
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Nissen
authors.affiliation: Department of Psychology, Sapienza University of Rome, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Lombardo
authors.affiliation: Department of Psychology, Sapienza University of Rome, Italy.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Violani
authors.affiliation: Department of Radiology, University of Freiburg Medical Center, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hennig
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Riemann
mesh_terms: D000328:Adult; D000679:Amygdala / Q000502:physiology*; D001007:Anxiety; D001143:Arousal / Q000502:physiology; D016022:Case-Control Studies; D004644:Emotions / Q000502:physiology; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008954:Models, Biological; D012890:Sleep / Q000502:physiology; D007319:Sleep Initiation and Maintenance Disorders / Q000503:physiopathology* / Q000523:psychology*
keywords: International Affective Picture System; amygdala; emotional arousal; emotional bias; emotional reactivity; emotional valence; habituation; insomnia disorder