Many people experience depression or a down mood in the winter. This condition is known as Seasonal Affective Disorder, or SAD. Doctors and researchers alike believe that depressive moods can be more common in the winter due to lack of sunlight exposure.
Sunlight exposure supports the production of two hormones in the body, melatonin and Vitamin D. Both melatonin and Vitamin D have been shown in studies to support a positive or up mood and deficiencies or irregularities in their production can cause a down or depressed mood.
Sunlight exposure on the top of the head stimulates the pineal gland to produce melatonin. Melatonin is the hormone responsible for regulating sleep cycles and healthy levels of this hormone improve the quality of sleep as well. Individuals with proper melatonin production will have more restful, deeper sleep and wake easier in the morning.
Sunlight exposure on bare skin causes a metabolic reaction that results in the production of Vitamin D. Although Vitamin D is found in many foods (dairy), the major source of Vitamin D for most adults is from our own production (in the skin). Vitamin D is involved in immune system function, bone health, and mood regulation. In studies Vitamin D deficiency has been directly linked to depression or depressive symptoms.
In many areas of the US and world the winter can be a very dark time. This is especially true for those who work inside, they may never see daylight because the sun rises after 8 am and sets before 5 pm. People who live in cities in the northern latitudes are more at risk for developing SAD.
There are several products/gadgets available on the market that are geared to simulate natural sunlight and help boost the production of both melatonin and Vitamin D. Researchers tested the effectiveness of three non-pharmaceutical treatments for SAD and published the results in the December issue of the American Journal of Psychiatry.
Bright light therapy with full spectrum bulbs, dawn simulation, and negative air ionization were all tested to determine the effect, if any, on symptoms of seasonal affective disorder in adults. Nearly 100 men and women who suffer SAD completed the study. Each person was randomly assigned to one of five groups that tested varying degrees of the three treatments.
Bright light therapy was given for 30 minutes after rising usually during the breakfast period. 57 percent of the participants receiving bright light therapy reported improvements in their symptoms.
Dawn simulation, which mimiced the rise of sun in May, was given before waking over a few hours time. This treatment improved symptoms in 50 percent of the subjects, while a brief dawn pulse, given over a shorter period of time only resulted in improvement in 43 percent of the participants.
Negative air ionization was also given the the participants before waking, which resulted in less hinderance on the schedule. The researchers tested the efficacy of both high and low negative ionization delivery. High negative air ionization resulted in improvement of 48 percent of participants. It was twice as effective than low negative air ionization which only resulted in improvement in 23 percent of the participants.
The authors concluded that both dawn simulation and high negative air ionization are as effective as bright light therapy to reduce the symptoms of SAD. Bright light therapy has been proven in other studies to significantly reduce symptoms of seasonal affective disorder and is considered a first line treatment recommendation.
If you think you may need a little extra sun in the winter, one of these treatments may be for you. Consult your healthcare provider to determine if the symptoms you are experiencing can be improved.
Posted by Dr. Christina Gutierrez on January 22, 2007 10:46 AM
