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Light Therapy for Depression

Janell Senda

Nov 9, 2008

 

 

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Intro

 

            Depression is a terrible psychological disorder that can strike many different kinds of people at various times in their lives.  When the feelings of hopelessness and anxiety that accompany depression are intrusive enough to interfere with one’s quality of life, doctors will often choose to intervene.  Therapy and anti-depressant medications are the traditional way in which doctors will treat their patients who present with depression symptoms.  However, these options can prove to be expensive and intrusive.  Therapy requires numerous visits to a psychologist’s office to even give hope of remission, while anti-depressants can result in both physical and personality-altering side effects in its user.  Legitimate alternative treatments for depression are few and far between.  However, in the past decades, a new treatment has emerged, with promising results: light therapy.

 

What is Light Therapy?

 

            Light therapy, also referred to as “bright light therapy” or “white light therapy” in various articles, is a process where a patient purposefully absorbs either natural or artificial UV rays.  Because of the convenience factor, many patients use artificial UV lights, such as LightBook, SunBox, or HappyLite.  By following manufacturers directions, which usually tell the consumer to sit with one’s eyes about two feet away, and slightly below the product.  By doing this for the recommended amount of time (depending on the bulb strength), the patient can have new hope for successfully treating their depression.

 

 

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Supporting Studies

 

            Since the connection was made between decreased light exposure during winter months and seasonal depression, doctors have been attempting to use artificial light to resolve it.  Because the results were favorable, doctors next tried to treat those with non-seasonal depression by way of light therapy.  So far, definitive answers have been few, but many studies have shown favorable results.  It has been shown that those who were exposed to UVA light, like the bulbs used in light therapy, “felt significantly more balanced, less nervous, and more strengthened,” creating an overall feeling of well being in participants.   (Gambichler 2002).  In fact, according to one study, depression patients “have consistently experienced antidepressant effects from bright light treatment” (Sumaya 2001 page M356).  Once it had been asserted that light therapy was beneficial, the question still loomed: is this alternative treatment comparable to traditional antidepressants?  The answer is yes.  The APA Committee on Research on Psychiatric Treatments said, “light Therapy is beneficial and effect sizes are comparable to those found in antidepressant drug trials” (Golden 2005).  Not only does this therapy work, but it has been found to work faster than any other credible treatment available. Light therapy is be an extraordinarily expedient way to achieve relief from all forms of depression. Studies have shown that it takes substantially less time to produce measurable effects than antidepressant drugs do (Martiny 2006).  A patient can often achieve some level of relief in just one session.

 

 

 

 

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Dissenting Studies

 

            There is no real dispute that light therapy does not work as a treatment for depression; however, some studies have revealed problems in the formation of a treatment plan using bright light.  First of all, “many studies of bright light have been small and have not received the financial backing that has been devoted to clinical trial of antidepressant drugs” therefore making them less tried and true than traditional treatments (Kripke 2006 page 163).  Because of this, doctors may not have complete data on the subject.  Also, there has been some dispute as to whether or not this treatment may have a negative effect on the patient’s eyes.  Even in the otherwise glowing article by Isabel Sumaya about how wonderfully successful light therapy was with her patients, the article does admit that “one patient discontinued bright light treatment, reporting that the light was too bright” (Sumaya 2001 page 359).  As far as manufacturer’s studies show, “light boxes are less risky than the sun.”  However, consumers must be aware of “a condition called macular degeneration. The most common version of this condition, which appears to be related to the amount of light hitting your retina over many years, is called "dry" macular degeneration.  Fortunately, this is a problem which takes years to develop.  It also appears that not everyone is susceptible” (http://www.psycheducation.org/depression/LightTherapy.htm).  However, it is also important to realize that there is currently no way to test one’s susceptibility to these things.  Another problem that doctors and patients have run into is the lack of a long-lasting effect on one’s depression.  Unfortunately, “the effect of bright light [on depression] is quickly lost after discontinuation;” in fact, “the effect gained by 5 weeks of bright light treatment is lost a mere 4 weeks after discontinuation of light treatment.” (Martiny 2006 page 1251).

 

Why Would This Work

 

            For centuries, sunlight has been used as a treatment for a variety of ailments.  While the specific claims vary in legitimacy, it is clear that sunlight has some therapeutic effects.  In the case of depression, it has been shown that “light is an important environmental factor for regulation of mood.”  This has been show by the “high frequency of seasonal affective disorder in high latitudes where light exposure is limited, and bright light therapy is a successful antidepressant treatment”  (Gonzalez 2008, page 1).   But what is the scientific basis for light therapy?  It has to do with chemistry in the brain.   It is the chemicals melatonin serotonin, which “affects emotional states… and other human rhythms” (Gambichler 2002 page 2).  Depression is associated with decreased function of these chemicals in the body (Gonzalaz 2008).   In otherwise healthy patients undergoing light therapy for depression, a marked increase in blood serotonin was recorded.  Therefore, by exposing oneself to light, the patient can hopefully increase his or her previously depleted serotonin levels, which leads to feelings of balance and well being in one’s life.

 

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Conclusion

 

            These dissenting studies do not offer directly contrary evidence to the supporting studies. This seems to point to a positive opportunity cost for light therapy.  Although most studies I came across show favorable results; more research would need to be done.  As the APA Committee on Psychiatric Treatment pointed out:

There is already some evidence to endorse the use of bright light treatment…  but further studies evaluating the use of bright light treatment as an adjunct to pharmacotherapy are clearly needed.”

           (Kripke 2006 page 163)

This alternative therapy seems to be beneficial, and worth a try for any patient who is not a good candidate for anti-depressant drugs, whose depression is not successfully controlled by them, or simply wants to try something different.  The results seem promising; perhaps one day soon antidepressant drugs will be obsolete.

 


Works Referenced

 

 

Golden; Gaynes; Ekstrom; Hamer; Jacobsen; Suppes; Wisner; Nemercroff.  American

Journal of Psychiatry. “The Efficacy of light therapy in the Treatment of Mood Disorders; a review and meta-analysis of the Evidence. “ Vol 162.  2005

 

Gonzalez; Aston-Jones. PNAS. “Light Deprivation Damages Monoamine Neurons and

Produces a Depressive Behavioral Phenotype in Rats.”  Vol 105, No 12.  March 25, 2008.

 

Kripke; Tuunainen; Endo.  American Journal of Psychiatry.  “Benefits of Light Treatment

for Depression.”  Vol 163, Issue 1.  January 2006.

 

Martiny; Lunde; Unden; Dam; and Bech. Psychological Medicine.  “The Lack of

Sustained Effect of Bright Light, After Discontinuation, in Non-seasonal Major

Depression.”  Vol 36.  2006.

 

 

Sumaya; Rienzi; Deegan; Moss.  Journal of Gerontology. “Bright Light Treatment

Decreases Depression in Institutionalized Older Adults:  A Placebo-Controlled

Crossover Study.”  Vol 56A, No 6. 2001.

 

http://www.psycheducation.org/depression/LightTherapy.htm

 

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