More about dawn Simulation and Research Abstracts - Part 1
Articles : Dangers of Blue Light & the Benefits of Dawn Simulation
What is Dawn Simulation?
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 individuals 'body clocks' respond to this stimulus by speeding up and reinforcing the 'waking-up process' so that they have more or less woken up even before their eyes open. It is important to note that a light coming on quickly does not have the same affect. We believe that 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 describing dawn simulation is to say that it regulates our body clocks so, after only a few days use, your sleep pattern adapts to the hours you are actually keeping. This means that you will be more ready to go to sleep earlier as well as get up earlier.
Dawn simulation is a great addition to light therapy for the treatment of Seasonal Affective Disorder.
The following abstracts are a small selection of the studies conducted on the efficacy of dawn simulation (The conclusions are highlighted)
Dawn simulation treatment of winter depression: a controlled study.
Avery DH, Bolte MA, Dager SR, Wilson LG, Weyer M, Cox GB, Dunner DL.
Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle.
OBJECTIVE: This study sought to determine whether dawn simulation was superior to a shorter dimmer "placebo" dawn signal in treating winter depression. METHOD: In a randomized, parallel design, 22 patients with winter depression were treated with either 1 week of a 2-hour dawn simulation peaking at 250 lux or 1 week of a 30-minute dawn simulation peaking at 0.2 lux. The subjects were told that they would receive either a "gradual" dawn or a "rapid" dawn reaching an intensity that would be dimmer than standard bright light treatment. At the end of both the baseline week and the treatment week, subjects were assessed in a blind manner with the Hamilton Rating Scale for Depression. Analysis of covariance was used to compare the two dawn treatments. RESULTS: The 2-hour, 250-lux dawn simulation resulted in Hamilton depression scale scores that were significantly lower than scores after the 30-minute, 0.2-lux dawn simulation. CONCLUSIONS: This study indicates that dawn simulation is an effective treatment for winter depression.
Dawn simulation compared with a dim red signal in the treatment of winter depression
Avery DH, Bolte MA, Wolfson JK, Kazaras AL.
Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle.
In a randomized, parallel design, 19 patients with winter depression were treated with either a week of a white 1.5-hr dawn simulation peaking at 250 lux or a week of a red, 1.5-hr dawn signal peaking at 2 lux. The subjects were told that they would receive either a white or red dawn reaching in intensity that would be dimmer than standard bright light treatment. At the end of both the baseline week and the treatment week subjects were blindly assessed with the Hamilton Rating Scale for Depression (HDRS). Analysis of covariance was used to compare the two dawn treatments. The white, 1.5-hr, 250 lux dawn simulation resulted in significantly (p < 0.05) lower HDRS scores compared to the red, 1.5-hr, 2 lux dawn. This is the second controlled study which indicates that dawn simulation is an effective treatment for winter depression.
A controlled study of dawn simulation in subsyndromal winter depression
Norden MJ, Avery DH.
Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle.
In a randomized, cross-over design, 16 subjects with recurrent autumn-winter symptoms but without major depression were treated with 4 days of dawn simulation consisting of a gradually increasing illuminance over 45 min peaking at 100 lx (slow dawn) and with 4 days of a light rapidly increasing over a 4 s period to 100 lx (rapid dawn). The slow dawn was significantly better than both baseline and the rapid dawn in improving subjective measures of energy, mood, social interest, productivity, quality of sleep and quality of awakening.
The effect of dawn simulation on the cortisol response to awakening in healthy participants
Thorn L, Hucklebridge F, Esgate A, Evans P, Clow A.
Department of Psychology, University of Westminster, 309 Regent Street, London W1R 8AL, UK.
Bright light exposure after awakening has been shown to elevate cortisol levels in healthy participants. The present study examined the effect of dawn simulation (a treatment for seasonal affective disorder) on the cortisol response to awakening and mood. Twelve healthy participants were supplied with a dawn simulator (The Natural Alarm Clock, Outside In, Cambridge Ltd), a bedside light that increases in intensity prior to awakening to approximately 250 lux over 30 mins when an audible alarm sounds. A counterbalanced study was performed on 4 consecutive normal weekdays, two of which were control days (no dawn simulation) and two experimental (dawn simulation). Saliva samples were taken immediately on awakening then at 15, 30 and 45 minutes post awakening on all 4 study-days. Total cortisol production during the first 45 mins after awakening was found to be significantly higher in the experimental condition than in the control condition. Participants also reported greater arousal in the experimental condition and there was a trend for an association between increased arousal and increased cortisol secretory activity under dawn simulation. This study provides supportive evidence for the role of light and the suprachiasmatic nucleus in the awakening cortisol response.
Is dawn simulation effective in ameliorating the difficulty awakening in seasonal affective disorder associated with hypersomnia?
Avery DH, Kouri ME, Monaghan K, Bolte MA, Hellekson C, Eder D.
University of Washington School of Medicine, Department of Psychiatry and Behavioral Sciences, Harborview Medical Center, 325 Ninth Avenue, Seattle, WA 98104, USA. averydh@u.washington.edu
BACKGROUND: Patients with winter depression, (seasonal affective disorder, SAD) frequently complain of difficulty awakening in the morning. Dawn simulation has been found effective in treating SAD, but its effect on difficulty awakening has not been assessed. METHODS: Fifty medication-free patients with SAD associated with hypersomnia were randomized to receive either 1 week of dawn simulation (250 lux) or a dim (0.2-2 lux) placebo signal. The patients assessed their level of drowsiness upon awakening during the baseline week and during the treatment week using the Stanford sleepiness scale (SSS). A psychiatrist rated difficulty awakening after the baseline week and after the treatment week. RESULTS: Dawn simulation lowered both the difficulty awakening score (P<0.05) and the SSS score (P<0.05) compared to the placebo dawn signal. LIMITATIONS: Replication is necessary. No biological markers of circadian phase were measured. CONCLUSIONS: Compared to a placebo condition, dawn simulation appears effective in decreasing both prospectively assessed morning drowsiness and retrospectively assessed difficulty awakening. The symptom of difficulty awakening is consistent with the phase delay hypothesis of SAD. Assessment of difficulty awakening could prove useful in the evaluation of SAD.