Dawn Simulation - Research Summary
Dawn Simulation is a technique using a light that comes on very slowly in the early morning, to imitate a natural sunrise. The key research finding is that our "body clocks" respond to this stimulus by speeding up and reinforcing the "waking-up process" so that we have, more or less, woken up even before our eyes open. It is important to note that a light coming on suddenly does not have the same effect. The explanation goes back to when mankind was evolving, and our systems adapted so that our ancestors woke with the sunrise, which their systems recognised as being a gradual increase of light.
Another way of
looking at the effect is to say that it acts as a regulator on our body
clocks, so that after a few days use your sleep pattern can become more
adapted to the hours you are actually keeping, meaning that you may become
more ready to go to sleep earlier as well as get up earlier. The Sunrise
Alarm Clock features a sunset/twilight go-to-sleep feature which, as Dr.
Terman found, "produces a pleasant hypnotic sensation which allowed
the patients to fall asleep easier, and seemed to help in resolving poor
Why should Seasonal Affective Disorder (SAD) sufferers be interested?
A number of research projects have been undertaken to see whether this might be helpful for SAD sufferers, and the answer is definitely YES. The idea is that part of SAD is connected with the body clock; the body clock is kept in regulation by light, and if the light signals are missing then the body clock loses regulation and so, for instance, it might be telling your system to go to sleep in what is actually the middle of the afternoon because it 'thinks' that it's late at night.
What's the evidence for this? I remember from my childhood hearing on the radio about some experiments in France, when people spent many weeks deep underground with only an intercom to connect them with the outside world, and with no clock or watch. After some days each subject started to get into a new pattern, where they would go to sleep not every 24 hours but, on average, every 26 or 27 hours, although some people's day length revised to as much as 30 hours, with a few experiencing days an hour or two shorter than 24.
So light is what regulates our body clocks.
Michael Terman (a famous name in the annals of SAD) and colleagues first tried out Dawn Simulation as a treatment in 1989. They established that at less than 500 lux it produced the drop in melatonin levels that most of us will have read about, with other evidence (looking at how much people move etc) to show that it produced a "phase advance", i.e. that the subjects' body clocks were running quicker. And most importantly it showed a marked reduction in SAD symptoms, with 6 of the 8 subjects showing "full clinical remission".
The subsequent research was performed by a team headed by David Avery (another well known name in SAD researchers' circles) in Seattle, which is a very overcast place for most of the year. This research tried a number of different timings and brightnesses, and some of the research was restricted to subjects with mild (sub syndromal) SAD. I would summarise these as follows:
1. If the dawn simulation is reasonably realistic it is effective. So a 2 hour time (from minimum light level of under 1 lux to full) was successful, so was 30 minutes, but 10 minutes produced mixed results and 30 seconds was no good. In nature, times of 2 hours to 30 minutes are common, but 10 minutes only really applies to the equator, and 30 seconds is not realistic at all. In essence it is a trick which somehow fools the mind into thinking you have experienced a real sunrise, and the body clock is adjusted to be in its early morning state.
2. The light level at full should be a lot less than you get from a light box. The levels of brightness at full varied between 100 lux and 1700 lux. They seem to be equally effective, except, naturally enough, a high brightness 'dawn', over 2 hours tended to wake people up early.
3. The benefits are felt in 1 or 2 days. Whereas light boxes take a week or more.
4. The benefits apply to severe and mild SAD sufferers alike. One large scale experiment selected only mild SAD sufferers, and it showed improvements in drowsiness, energy, mood, social interest, concentration, productivity, quality of awakening, and quality of sleep. For more severe sufferers the symptoms scores reduced from averages of 19 down to averages of 6, which is the same general improvement as you would expect from light boxes.
5. Itís nice. The experimenters say that users liked it. I agree with them, it is a better way to wake up.
A final quote from a paper at the summer 1993 SLTBR (researchers') conference: "Because dawn simulation occurs during sleep it is very convenient unlike conventional bright light therapy. This convenience is likely to result in a higher degree of compliance than with bright light therapy (i.e. you are more likely to do it every day). Dawn Simulation produces a degree of improvement similar to that seen in previous studies with light boxes."
What does Norman Rosenthal say? From his new book: "I personally use a dawn simulator each day, and find that it really helps me to wake up in the morning .... I take it along with me whenever I travel during the winter months."
The Natural Alarm Clock is the world's first fully integrated Dawn Simulator. It includes a lamp, with a built-in dimmer so it also serves as a beautiful and sophisticated bedside light, as well as providing the gentle dawn simulation function. For new users, who are often anxious that it might not wake them up, it includes an audible alarm after the light has reached full brightness, although most people find that they are fully awake just in time to prevent the beeper sounding.
Steve Hayes, Managing Director, Outside In
Adapted from an
article for the SADA newsletter, January 1994
Dawn Simulation Treatment for Winter Depression
by D. Avery
Society SLTBR Abstracts, June 1993
AB Reviewing four
previous studies, the author states that the degree of improvement with
dawn simulation is similar to that seen in previous studies of bright
Dawn Simulation in Teenage Children
by G. Brainard
80% or more of
the subjects who used the (Natural Alarm Clock) and their parents found
ease of waking superior (twice as easy as usual) and preferred it to other
methods of awakening. Since the clock is a .. novel technology placebo
effect could not be ruled out.
Study of Dawn Simulation Treatment
by D. Norden Avery, MF
Acta Psychiatr Scandinivica, July 1993 88(1):67-71
was well tolerated and resulted in marked improvement in a group of subsyndromal
SAD subjects. Both the rapid (placebo) and slow conditions were associated
with an improvement over baseline but there was a significant dose response
effect favouring the longer dawn signal.