Light therapy (also called phototherapy) has been studied as a treatment for seasonal depression for more than 20 years. More recently it has been established as an effective treatment for nonseasonal depressional as well. Several studies have shown lightboxes can achieve significant relief from depression more than four times faster than medication. They are even more effective for people over 65.
What kind of light to use
Both natural sunlight and commercial lightboxes have been shown to treat depression effectively. When thinking about whether to purchase an artificial lightbox, you should know that sunlight reaches levels of 100,000 lux, while the most powerful home lightboxes produce only about one-tenth of that amount of light. However, being able to be exposed to bright lights while indoors is more convenient for many people, and depending on your latitude, the sun may only be high enough to be able to produce vitamin D for a few hours around midday.
Therapeutic exposure to a 10,000 lux lightbox is 30 minutes a day. Some studies indicate that doing light therapy as close to dawn as possible increases effectiveness, while others suggest that time of day is not important. If you are choosing to use sunlight, one half hour on a clear day at midday is ideal.
Whether you choose natural sunlight or a lightbox, it is very important that you do not use any sunscreen. Sunscreen blocks your body’s ability to produce vitamin D, which is believed to play an important role in causing and treating depression. If you believe your depression might be caused by a vitamin D deficiency, you should also take a vitamin D suppliment.
Click here for an ideal lightbox. (This site receives no commission for sales.)
Research on Sunlight and Lightboxes for Depression
Terman, M; Terman, J. Light Therapy for Seasonal and Nonseasonal Depression: Efficacy, Protocol, Safety, and Side Effects. CNS Spectr. 2005;10(8):647-663.
Bright light therapy is well recognized as an extremely effective treatment for seasonally-related depression, specifically Seasonal Affective Disorder. Treatment ranges from 2,500 to 10,000 lux for 2 hours to .5 hours respectively. For Major Depression, light therapy produces results after one only week that medications do not achieve until 4-16 weeks. Light therapy is particularly effective with elderly people.
G . Lambert , C . Reid , D . Kaye , G . Jennings , M . Esler. Effect of sunlight and season on serotonin turnover in the brain. The Lancet , Volume 360 , Issue 9348 , Pages 1840 – 1842
The rate of production of serotonin by the brain was directly related to the prevailing duration of bright sunlight (r=0·294, p=0·010), and rose rapidly with increased luminosity. Our findings are further evidence for the notion that changes in release of serotonin by the brain underlie mood seasonality and seasonal affective disorder.
Isabel C. Sumaya. Beth M. Rienzib, Jess F. Deegan, IIb and Donald E. Mossa. Bright Light Treatment Decreases Depression in Institutionalized Older Adults: A Placebo-Controlled Crossover Study. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences 56:M356-M360 (2001).
Scores on the Global Depression Scale (GDS) remained unchanged during the placebo and control conditions, but depression scores decreased significantly during the 10,000 lux treatment (pretest GDS M = 15 vs posttest GDS M = 11, p < .01). After the 10,000 lux treatment, 50% of the participants no longer scored in the depressed range. Improvement during the 10,000 lux condition was positively correlated (r = .62, p < .05) to baseline GDS scores, where participants with higher GDS scores experienced greater improvement following the 10,000 lux treatment.
Charmane I. Eastman, PhD; Michael A. Young, PhD; Louis F. Fogg, PhD; Liwen Liu, PhD; Patricia M. Meaden, PhD. Bright Light Treatment of Winter Depression: A Placebo-Controlled Trial. Arch Gen Psychiatry. 1998;55:883-889.
However, strict response criteria revealed statistically significant differences; after 3 weeks of treatment morning light produced more of the complete or almost complete remissions than placebo. By 1 criterion (24-item SIGH-SAD score <50% of baseline and <=8), 61% of the patients responded to morning light, 50% to evening light, and 32% to placebo after 4 weeks of treatment.
Avery DH, Bolte MA, Dager SR, Wilson LG, Weyer M, Cox GB, Dunner DL. Dawn simulation treatment of winter depression: a controlled study. Am J Psychiatry. 1993 Jan;150(1):113-7.
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.
Joan Arehart-Treichel. In Treating Nonseasonal Depression, Let the Light Shine In. Psychiatr News Sept, 2005 Volume 40, Number 17, page 14.
They found that light was somewhat more efficacious in subjects who had been exposed to light during the winter than in subjects who had been exposed to light in months outside of winter, but the difference was not significant.
Gloth FM 3rd, Alam W, Hollis B.Vitamin D vs broad spectrum phototherapy in the treatment of seasonal affective disorder. J Nutr Health Aging. 1999;3(1):5-7.
All subjects receiving vitamin D improved in all outcome measures. Subjects receiving vitamin D improved more than those receiving phototherapy.
B.-E. Thalén, B.F. Kjellman, L. Mørkrid, R. Wibom, L. Wetterberg. Light treatment in seasonal and nonseasonal depression. Acta Psychiatrica Scandinavica. Volume 91 Issue 5, Pages 352 – 360.
Depressed patients with seasonal pattern improved significantly more than those with a nonseasonal pattern suggesting a specific nonplacebo effect of light treatment in depressed patients with seasonal pattern. There were no significant differences in outcome when light treatment was given in the morning or in the evening, and not between patients with and without atypical symptoms such as carbohydrate craving or increased appetite.
Daniel F. Kripke. Light treatment for nonseasonal depression: speed, efficacy, and combined treatment. Journal of Affective Disorders. Volume 49, Issue 2, May 1998, Pages 109-117.
Light treatment of nonseasonal depression produces net benefits in the range of 12–35%, often within 1 week. Conclusions: Light’s value for nonseasonal and seasonal depression are comparable. Light appears to produce faster antidepressant benefits than psychopharmacologic treatment.
