We have discussed the extraordinary ability of sunlight exposure or other bright-light exposure to profoundly increase the production of serotonin, a brain chemical that is a potent mood enhancer. The most remarkable research on this subject was by Dr. Gavin Lambert and his colleagues in Australia. They measured serotonin levels in response to varying degrees of bright light. To do this, they actually took blood samples from internal jugular veins of 101 men and compared the serotonin concentration of the blood to weather conditions and seasons. The results were remarkable: MEN WHO WERE MEASURED ON A VERY BRIGHT DAY PRODUCED EIGHT TIMES MORE SEROTONIN THAN THOSE WHO WERE MEASURED ON A CLOUDY, DISMAL DAY. They also observed that the effect of bright light was immediate, and that there was no holdover from day to day. SEROTONIN LEVELS WERE ALSO SEVEN TIMES HIGHER IN SUMMER THAN WINTER. NO WONDER WE FEEL SO GOOD WHEN WE ARE OUTSIDE IN THE SUMMERTIME!
The most popular anti-depressant drugs also work by keeping serotonin levels higher, but there are frightening side-effects. The Food and Drug Administration (FDA), indicates that antidepressant medications known as selective serotonin re-uptake inhibitors (SSRI’s) may increase depression in some cases and lead to suicidal thoughts. Some of the brands involved are Paxil, Lexapro, Prozac, Effexor, Zoloft, Wellbutrin, Luvox, Celexa and Serzone, although the FDA listed 34 drugs. The entire list is at fda.gov/cder/drug/antidepressants/. They state the following: “The Food and Drug Administration asks manufacturers of all antidepressant drugs to include in their labeling a boxed warning and expanded warning statements that alert health care providers to an increased risk of suicidality in children and adolescents being treated with these agents, and additional information about the results of pediatric studies.”
The FDA lists several additional warnings and instructions about these drugs:
Antidepressants increase the risk of suicidal thinking and behavior (suicidality) in children and adolescents with MDD (major depressive disorder) and other psychiatric disorders.
Anyone considering the use of an antidepressant in a child or adolescent for any clinical use must balance the risk of increased suicidality with the clinical need.
Patients who are started on therapy should be observed closely for clinical worsening, suicidality, or unusual changes in behavior.
Families should be advised to closely observe the patient and to communicate with the prescriber.
Missing are two important facts: (1) SSRI’s increase bone loss. Women who used SSRI’s lose nearly 80% more bone per year than non-users! And as expected, later research shows that SSRI use correlated to a 75% greater likelihood of sustaining a fracture. Secondly, SSRI’s don’t work very well. A meta-analysis of data on SSRI’s submitted to the FDA indicates that placebos (sugar pills) are as effective as SSRI’s in reducing depression;  in other words, only drug companies benefit from SSRI’s—not depression sufferers.
Based on that information, it seems prudent to increase our endorphins (and our happiness) through sunlight exposure. It is what nature intended.
 Lambert GW, Reid C, Kaye DM, Jennings GL, Esler MD. Effect of sunlight and season on serotonin turnover in the brain. Lancet. 2002 Dec 7;360(9348):1840-2.
 Diem SJ, Blackwell TL, Stone KL, Yaffe K, Haney EM, Bliziotes MM, Ensrud KE.. Use of antidepressants and rates of hip bone loss in older women; the study of osteoporotic fractures. Arch Intern Med 2007:167:1231-32.
 Sheu YH, Lanteigne A, Stürmer T, Pate V, Azrael D, Miller M5. SSRI use and risk of fractures among perimenopausal women without mental disorders. Inj Prev. 2015 Jun 25. pii: injuryprev-2014-041483. doi: 10.1136/injuryprev-2014-041483. [Epub ahead of print]
 Kirsch, I. et al. Initial severity and antidepressant benefits: a meta-analysis of data submitted to the Food and Drug Administration. PLoS Medicine 2008;5:e45. doi:10.1371/journal.pmed.0050045
By Marc Sorenson, EdD
Drs. Asta Juzeniene and Johan Moan wrote a paper in 2012 that beautifully summarizes the effects of sunlight beyond the production of vitamin D. Here are the highlights of their paper, as stated in the abstract. They discuss the separate affects of Ultraviolet B light (UVB) and ultraviolet A light (UVA), which are, of course, components of sunlight.
- UVB induces cosmetic tanning (immediate pigment darkening, persistent pigment darkening and delayed tanning).
- UVB-induced, delayed tanning acts as a sunscreen.
- Several human skin diseases, like psoriasis, vitiligo, atopic dermatitis and localized scleroderma, can be treated with sunlight or artificial UV radiation (phototherapy).
- UV exposure can suppresses multiple sclerosis independently of vitamin D synthesis.
- UVA generates nitric oxide (NO), which may reduce blood pressure and generally improve cardiovascular health.
- UVA induced NO may also have antimicrobial effects.
- UVA induced NO may act as a neurotransmitter.
- UV exposure may improve mood through the release of endorphin.
It wasn’t mentioned in the paper, but we now know that sunlight also helps generate serotonin in the brain, which improves mood, and outside the body it is a potent disinfectant (see my recent blogs on those subjects). So those who claim that sunlight is harmful in any amount, must be living on a different planet. Embrace the Sun, but never burn.
 Asta Juzeniene and Johan Moan. Beneficial effects of UV radiation other than via vitamin D production. Dermato-Endocrinology 4:2, 109–117; April/May/June 2012.