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| SAD Light therapy |
Seasonal affective disorder is a recurrent melancholy mood that tends to come on in the fall and winter, and subside in the spring and summer months.
Symptoms include:
· Depressed mood
· Weight gain
· Hypersomnia or insomnia
· Fatigue
· Social withdrawal
· Carbohydrate cravings
· Anxiety or irritability
· Difficulty concentrating
According to the National Mental Health association an estimated 10 million people are affected by SAD each year. Among the causes are less daylight during the fall and winter, increased melatonin, low vitamin D, genetics and age. The most popular and least invasive treatment for SAD is phototherapy. The idea of using light therapeutically for winter blues is credited to a study from 1984 by Norman Rosenthal et al in which the SAD was first defined. Phototherapy requires a light source of 10,000 lux.
For a frame of reference:
· On a bright sunny day, daylight provides about 20,000 lux
· On a cloudy day daylight provides 5,000 lux.
· Office fluorescent lighting provides 300-500 lux
· Typical lighting in a living room 100 lux.
At 10,000 lux the total time of exposure should be around 30 minutes. If your light source is 5,000 lux then you need 60 minutes of exposure. SAD lights do not emit UV rays and are considered safer than tanning beds for this reason. The therapy works best if your eyes are open and you are actually doing something productive, like reading or sewing, or working on a puzzle. Most lights require that the distance you sit from the light is 12-20 inches in order to get the full dose of light exposure.
One might consider using a tanning bed to treat SAD, and in northern climates, tanning is very popular in the winter. Evidently, tanning and UV exposure improves mood and sense of well being. It can make you feel so good in fact, that there is an addictive quality to it. Some scientists postulate that UV light increases endorphin levels. In one study Naltrexone, a drug that blocks the release of endorphins, was administered to frequent tanners and resulted in typical withdrawal like symptoms. This suggests that UV light exposure can cause an increase in endorphins. Since endorphins can be addicting we have a double edged sword here- UV light makes you feel good, but can be addicting! It seems safer when treating SAD to use an SAD light that does not emit UV rays.
Low vitamin D levels are correlated with SAD but whether there is a causal relationship is still being studied. Vitamin D levels have been associated with depression and vitamin D levels are typically lowest in the winter. Thus the connection between the winter blues and low Vitamin D. A pilot study from the journal Applied Nursing Research by Shipowick et al. suggests that supplementing with Vitamin D in the winter months reduces symptoms of depression. While scientific proof is pending, why not make sure levels of vitamin D are within normal range? Vitamin D deficiency is easy to test and treat and has far reaching benefits beyond depression and fatigue.
Melatonin, a hormone produced by the pineal gland helps in regulating the circadian rhythm. Its production is decreased by light and increased by darkness. In SAD, melatonin levels are often found to be higher in the winter than in the summer. Blue colored light is primarily what suppresses melatonin and many light boxes made for SAD phototherapy are blue light. Here is a link to one blue light.
Medications are also often used to treat SAD, especially in people for whom light therapy is contraindicated (eg. macular degeneration). Antidepressants like serotonin reuptake inhibitors are the most commonly used. Buproprion, which is not an SSRI, is the first drug to receive FDA approval for treating SAD. An interesting study came out of Canada showing similar results in improving SAD with prozac or light therapy. Light therapy has no side effects, prozac and other medications have too many side effects to list here. If you are feeling the winter blues, remember there are simple and effective ways to help.
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