What is it?
In dawn simulation, a low but progressive level of light is provided for a prescribed period of a time, during the early morning, while the person remains asleep.
Dawn simulation is not intended to wake the sleeper, but rather to supply a signal of emerging sunrise. This signal brings circadian rhythms into synchrony with the natural sleep cycle, lessening depressive symptoms.
Because it is used during sleep and does not require earlier awakening, many people find dawn simulation more user-friendly than bright light therapy.
What does it treat?
Dawn simulation has been found to be as effective as bright light therapy in the treatment of Seasonal Affective Disorder. [9, 41, 42, 43]
References
9. Golden, R.N., et al., The efficacy of light therapy in the treatment of mood disorders: a review and meta-analysis of the evidence. American Journal of Psychiatry, 2005. 162(4): p. 656-62.
41. Terman, M., et al., Controlled trial of naturalistic dawn simulation and negative air ionization for seasonal affective disorder.[Erratum appears in Am J Psychiatry. 2007 Mar;164(3):529]. American Journal of Psychiatry, 2006. 163(12): p. 2126-33.
42. Terman, M. and T. Jiuan Su, Circadian Rhythm Phase Advance with Dawn Simulation Treatment for Winter Depression. Journal of Biological Rhythms, 2010. 25(4): p. 297-301.
43. Avery, D.H., et al., Dawn simulation and bright light in the treatment of SAD: a controlled study. Biological Psychiatry, 2001. 50(3): p. 205-16.