Sleep and Biological Rhythms

, Volume 14, Issue 1, pp 97–105

A new light source (Valkee©) does not alter sleep–wake parameters and does not improve mood in phase delayed subjects

  • Ståle Pallesen
  • Øystein Nødtvedt
  • Ingvild West Saxvig
  • Bjørn Bjorvatn
Original Article

DOI: 10.1007/s41105-015-0027-5

Cite this article as:
Pallesen, S., Nødtvedt, Ø., Saxvig, I.W. et al. Sleep Biol. Rhythms (2016) 14: 97. doi:10.1007/s41105-015-0027-5

Abstract

Not much evidence exists concerning the effects on sleep and mood of transcranial bright light. In this study, 50 students, all with wake-up time 9:00 a.m. or later in weekends/free days, participated in a double-blind placebo-controlled experiment comparing the effects of bright light (n = 27; 8.0 lm) and placebo (n = 23; 0.1 lm). Data collection consisted of sleep assessment, with both sleep diaries and actigraphy. In addition, the Fatigue Severity Scale and the Profile of Mood States (POMS) were administered. Following 1 week of baseline recording, the therapy was initiated, aiming to phase advance the sleep–wake period. The therapy lasted for 2 weeks and consisted of gradually advancing daily light exposure of 12 min’ transcranial bright light. Subjects in the two conditions did not change differently from baseline to post-treatment on any sleep parameters. A significant condition × time interaction was found for one of six subscales (vigor–activity) of the POMS, suggesting a more favorable development from baseline to post-treatment in the placebo compared to the bright light condition. No differences in terms of side-effects were reported between conditions. It is concluded that transcranial bright light, at times where conventional light therapy has phase-advancing properties, did not influence any sleep parameters differently than placebo. Transcranial bright light was associated with a less favorable development from baseline to post-treatment on one mood parameter compared to placebo.

Keywords

Transcranial bright light Sleep–wake rhythm Mood Randomized controlled trial 

Copyright information

© Japanese Society of Sleep Research 2015

Authors and Affiliations

  • Ståle Pallesen
    • 1
    • 2
  • Øystein Nødtvedt
    • 1
  • Ingvild West Saxvig
    • 2
  • Bjørn Bjorvatn
    • 2
    • 3
  1. 1.Department of Psychosocial ScienceUniversity of BergenBergenNorway
  2. 2.Norwegian Competence Center for Sleep DisordersHaukeland University HospitalBergenNorway
  3. 3.Department of Global Public Health and Primary CareUniversity of BergenBergenNorway