Dawn simulation research

This is just some of the research into dawn simulation and its beneficial effects on sleep, waking, mood and energy.

Effects of dawn simulation on markers of sleep inertia and post-waking performance in humans
Eur J Appl Physiol. 2014 Feb 11.
The Research Institute for Sport and Exercise Sciences at Liverpool John Moores University used Bodyclock Active to see what impact waking up with light would have on performance. They recruited eight subjects that were prone to sleep inertia (waking up with that groggy, still-half-asleep feeling) to come in to their Chronobiology Laboratory for a two-part sleep study. Compared with waking in dim light, the 30-minute sunrise left subjects feeling more refreshed and alert on waking up. During the first couple of hours after waking, various cognitive tests showed that average reaction times in this group were significantly quicker. There was also a physical challenge, to complete a 4km cycling time-trial as fast as possible; waking up with light shaved an average of 21 seconds from their time. Read the full abstract

Effects of artificial dawn and morning blue light on daytime cognitive performance, well-being, cortisol and melatonin levels
Chronobiol Int. 2013 Oct;30(8):988-97.
This study shows some of the all-round benefits of waking up with light. Subjects woke up with dawn simulation or had a 20-minute session of monochromatic blue light (BL) shortly after waking. Throughout the day, they took part in mental tests and completed questionnaires about their sleepiness, mood, etc. Those that had woken up with dawn simulation (DS) did better on the cognitive tests and reported improved mood and well-being, differences that were sustained all day. This seems to be linked to raised levels of cortisol on waking (only seen in the DS group) and the body's response to it rather than any effect on melatonin production (which only altered in the BL group; blue light is known to be particularly effective at shifting circadian rhythms). Read the full abstract

Effects of artificial dawn on subjective ratings of sleep inertia and dim light melatonin onset.
Chronobiol Int. 2010 Jul;27(6):1219-41.
In this study, waking up with dawn simulation resulted in a significant reduction of sleep inertia complaints though there was no shift in melatonin production or other circadian rhythms. Read the full abstract

Controlled trial of naturalistic dawn simulation and negative air ionisation for seasonal affective disorder
Am J Psychiatry. 2006 Dec;163(12):2126-33.
This trial looked at the effect of awakening with light or ionisation on winter depression. There were five different treatment groups: all improved depression scores with bright light producing the best results and low density ionisation having only a modest effect. Dawn simulation and high density ionisation got a special mention as they were not only very effective, they had the added advantage of not requiring any extra time or effort!  Read the full abstract

The effect of dawn simulation on the cortisol response to awakening in healthy participants
Psychoneuroendocrinology. 2004 Aug;29(7):925-30.
Twelve healthy volunteers used an early version of Bodyclock to wake them up. Samples were taken after waking and tested for cortisol, a hormone that helps to give the body a quick burst of energy and improve alertness. People waking up with our dawn simulators had significantly higher levels of cortisol and felt more awake.  Read the full abstract

Effect of dawn simulation on quality of sleep - a community based trial
BMC Psychiatry. 2003 Oct 27;3:14.
Dawn simulation was useful in treating SAD and winter depression but would it benefit people in general? 100 volunteers used a dawn simulator at home and rated their quality of sleep each morning. After six days there were definite improvements but the effects didn't last once they'd stopped using their dawn simulator. For best results, use your Bodyclock every day.  Read the full abstract

Is dawn simulation effective in ameliorating the difficulty awakening in seasonal affective disorder associated with hypersomnia?
J Affect Disord. 2002 May;69(1-3):231-6.
People with SAD often find it really hard to wake up and this study showed that dawn simulation could be of particular benefit. After one week of waking with dawn simulation, SAD sufferers were assessed and had considerably lower scores in respect of difficulty awakening and sleepiness.  Read the full abstract

The human circadian pacemaker can see by the dawn's early light
J Biol Rhythms. 2000 Oct;15(5):437-46.
Subjects were exposed to a controlled 24-hr cycle of very low light/darkness in which half the group started their 'day' with dawn simulation. After 6 days, hormone levels showed that those without dawn simulation were out of sync with their environment. Those that woke up with dawn simulation maintained their internal body clock suggesting that gradual change in light is a strong circadian signal.  Read the full abstract

Dawn simulation vs. lightbox treatment in winter depression: a comparative study
Acta Psychiatr Scand. 1998 Jul;98(1):73-80.
61 people with winter depression were involved in this study. They received either 2hrs of morning bright light therapy at a clinic or tried dawn simulation at home. Patients in both groups felt better and this was reflected in their reduced depression scores, on average 57% lower in those using bright light and 40% lower with dawn simulation.  Read the full abstract

A controlled study of dawn simulation in subsyndromal winter depression
Acta Psychiatr Scand. 1993 July;88(1):67-71
Dawn simulation resulted in marked improvement in a group of people with subsyndromal SAD (winter blues, rather than full SAD). A slow, gradual sunrise taking 45 minutes was much more effective than one lasting just a few seconds and subjects had better scores for energy, mood, social interest, productivity, quality of sleep and quality of awakening.  Read the full abstract