REM sleep as a potential indicator of hyperarousal in psychophysiological and paradoxical insomnia sufferers

Int J Psychophysiol. 2015 Mar;95(3):372-8. doi: 10.1016/j.ijpsycho.2015.01.005. Epub 2015 Jan 14.


Study objectives: The objective was to study REM sleep macrostructure and microstructure as potential indicators of hyperarousal in insomnia by comparing good sleepers (GS) and insomnia sufferers (INS) (subdivided into psychophysiological "PSY-I" and paradoxical "PARA-I").

Design: Cross-sectional comparisons of GS, PSY-I and PARA-I.

Setting: Participants slept for 4 consecutive nights in the laboratory where PSG was recorded. Nights 2 and 3 were combined to compare REM sleep between groups.

Participants: Thirty-nine PSY-I, 27 PARA-I and 47 GS completed the study, comprising home questionnaires, clinical interviews and night PSG recordings. All participants were aged between 25 and 55 and met inclusion criteria for either PSY-I, PARA-I or GS.

Interventions n/a measurements and results: Results showed no between group differences on REM sleep macrostructure. As for REM sleep microstructure, PSY-I had an increased number of wake intrusions compared to PARA-I (p=.03). Subjective SE, TST and TWT were significantly correlated with the duration of REM sleep (REMD; p≤.002) and with the proportion of REM sleep for PARA-I (p≤.06).

Conclusions: REM sleep macrostructure does not seem to be an adequate indicator of hyperarousal in insomnia. However, the number of wake intrusions in REM could be used to differentiate PSY-I from PARA-I and could reflect the heightened arousal of the former group. Relationships between REM sleep duration and proportion could be linked to dream imagery activity, especially in PARA-I. Further investigations are needed to identify variables that could reflect hyperarousal and differentiate insomnia types.

Keywords: Arousals; Hyperarousal; Insomnia; Macrostructure; Microstructure; REM sleep.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analysis of Variance
  • Arousal / physiology*
  • Cross-Sectional Studies
  • Electroencephalography
  • Female
  • Humans
  • Male
  • Middle Aged
  • Polysomnography
  • Psychophysiology*
  • Sleep Initiation and Maintenance Disorders / diagnosis*
  • Sleep Initiation and Maintenance Disorders / physiopathology*
  • Sleep, REM / physiology*
  • Time Factors