title: Types of primary insomnia: is hyperarousal also present during napping?
abstract: OBJECTIVE
  The objective of this study was to identify if hyperarousal is a 24-hour phenomenon in insomnia by comparing sleep during napping between good sleepers (GS) and Insomnia sufferers (INS) (subdivided into paradoxical "PARA-I" and psychophysiological "PSY-I") following a mentally challenging battery of cognitive tests.
  
  
  METHODS
  Cross-sectional comparisons of GS, PSY-I, and PARA-I.
  
  
  METHODS
  Participants slept for 4 consecutive nights in the laboratory where PSG was recorded. Upon awakening on mornings 2 and 3, cognitive testing (lasting 90-120 min) was administered, followed by a 20-minute nap.
  
  
  METHODS
  Fourteen PSY-I, 12 PARA-I, and 23 GS completed the study, comprising home questionnaires, clinical interviews, night PSG recordings, cognitive testing, and nap PSG recordings. All participants were between 25 and 50 years of age and met inclusion criteria for PSY-I, PARA-I, or GS.
  
  
  METHODS
  N/A.
  
  
  RESULTS
  On objective nap parameters, GS had a longer total sleep time (TST; p = 0.008) and better sleep efficiency (SE; p = 0.009), than PSY-I and PARA-I, and both groups of INS were awake significantly longer than GS (p = 0.003). Also, PARA-I took significantly more time than GS to fall asleep (p = 0.014). Subjectively reported sleepiness was comparable across the three groups. Positive relationships were observed between SE over the night and SE over the nap the following day.
  
  
  CONCLUSIONS
  Results show that GS sleep better than INS during naps following prolonged cognitive testing, suggesting that, in INS, hyperarousal predominates over mental fatigue resulting from these tests. These results may parallel what is observed at night when INS experience increased cognitive load but are unable to fall asleep.
authors: École de psychologie, Université Laval, Québec, Canada ; Laboratoire de Neurosciences Comportementales Humaines du Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Québec, Canada.
authors: Alexandra D
authors: AD
authors: Pérusse
authors: Isabelle
authors: I
authors: Turcotte
authors: Geneviève
authors: G
authors: St-Jean
authors: Jason
authors: J
authors: Ellis
authors: Carol
authors: C
authors: Hudon
authors: Célyne H
authors: CH
authors: Bastien
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007407:Interviews as Topic / Q000379:methods; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods; D007319:Sleep Initiation and Maintenance Disorders / Q000503:physiopathology*; D012894:Sleep Stages / Q000502:physiology*; D011795:Surveys and Questionnaires; D013647:Task Performance and Analysis; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology
keywords: Insomnia; hyperarousal; napping