The Effects of a Blue Monochromatic Light Intervention on Evening-type Individuals' Sleep and Circadian Rhythms
Circadian Rhythm Sleep Disorder, Delayed Sleep Phase, Sleep
About this trial
This is an interventional treatment trial for Circadian Rhythm Sleep Disorder, Delayed Sleep Phase focused on measuring Circadian rhythm, Sleep, evening-type individuals, morningness-eveningness, blue light, monochromatic light, randomized controlled trial
Eligibility Criteria
Inclusion Criteria:
- Scoring below 42 on the Horne-Östberg Morningness-Eveningness Questionnaire, as this categorizes moderate and definitely evening types (Horne & Östberg, 1976).
Exclusion Criteria:
- Participants will be excluded if a positive case is indicated on the Mood Disorder Questionnaire (MDQ), indicating the presence or history of bipolar disorder.
- Participants will also be excluded if they have worked night shifts during the past three months.
Sites / Locations
- University of Bergen
Arms of the Study
Arm 1
Arm 2
Experimental
Active Comparator
Blue monochromatic light
Full spectrum light control condition
Three consecutive mornings of one hour exposure to monochromatic light (20 lx, irradiance = 49.65 µW/cm2) with peak wavelength of 455 nm (blue light), with equal photon flux as the control condition.
Three consecutive mornings of one hour exposure to full spectrum light (2500 Kelvin, irradiance = 37.72 µW/cm2) with equal photon flux as the blue light. We will adjust the light intensity to make sure that the photon energy is the same across the two conditions.