The effects of low-intensity narrow-band blue-light treatment compared to bright white-light treatment in sub-syndromal seasonal affective disorder

BMC Psychiatry. 2016 Feb 18;16:27. doi: 10.1186/s12888-016-0729-5.


Background: The discovery of a novel photoreceptor in the retinal ganglion cells with a highest sensitivity of 470-490 nm blue light has led to research on the effects of short-wavelength light in humans. Several studies have explored the efficacy of monochromatic blue or blue-enriched light in the treatment of SAD. In this study, a comparison has been made between the effects of broad-wavelength light without ultraviolet (UV) wavelengths compared to narrow-band blue light in the treatment of sub-syndromal seasonal affective disorder (Sub-SAD).

Method: In a 15-day design, 48 participants suffering from Sub-SAD completed 20-minute sessions of light treatment on five consecutive days. 22 participants were given bright white-light treatment (BLT, broad-wavelength light without UV 10 000 lux, irradiance 31.7 Watt/m(2)) and 26 participants received narrow-band blue light (BLUE, 100 lux, irradiance 1.0 Watt/m(2)). All participants completed daily and weekly questionnaires concerning mood, activation, sleep quality, sleepiness and energy. Also, mood and energy levels were assessed by means of the SIGH-SAD, the primary outcome measure.

Results: On day 15, SIGH-SAD ratings were significantly lower than on day 1 (BLT 54.8 %, effect size 1.7 and BLUE 50.7 %, effect size 1.9). No statistically significant differences were found on the main outcome measures.

Conclusion: Light treatment is an effective treatment for Sub-SAD. The use of narrow-band blue-light treatment is equally effective as bright white-light treatment.

Trial registration: This study was registered in the Dutch Trial Register (Nederlands Trial Register TC = 4342 ) (20-12-2013).

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Affect / radiation effects
  • Female
  • Humans
  • Interview, Psychological / methods
  • Light*
  • Male
  • Middle Aged
  • Phototherapy* / instrumentation
  • Phototherapy* / methods
  • Seasonal Affective Disorder* / diagnosis
  • Seasonal Affective Disorder* / therapy
  • Sleep Stages / radiation effects
  • Surveys and Questionnaires
  • Time Factors
  • Treatment Outcome

Associated data

  • NTR/TC-4342