Seasonal Affective Disorder (SAD) is a particular kind of major depression that recurs at definite times of the year; most commonly in the fall, from September through to November. The symptoms show signs of abating from around March through May.
People who suffer from SAD are affected by the amount of daylight exposure they receive. The hormone melatonin, which helps regulate hormone secretion, body temperature and sleep, is produced in the brain during hours of darkness. The decrease in daylight hours in autumn and winter causes an increased production of melatonin in SAD sufferers, which results in the onset of debilitating symptoms of depression. Exposure to bright light is effective in the treatment of seasonal affective disorder.
The incidence of SAD as well as its severity is influenced by several factors including geographical location, family history of SAD, recent illness or spending a major portion of the day in a windowless room. Light therapy works on the principle that exposure to bright light can suppress the production of melatonin in the brain, which regulates the internal clock of the body and reduces symptoms.
A light box is a small portable device that is comprised of fluorescent tubes or bulbs. It is specially designed to provide a precise amount of balanced spectrum light that is equivalent to being out in the sun on a clear, sunny spring day. In mimicking outdoor light, the light box causes biochemical changes in the brain that help in synchronizing wake/sleep patterns, regulating the body clock and relieving symptoms of SAD.
During Light Box Therapy the user is required to sit directly in front of the light box at a specific distance, which depends upon the required intensity. For light therapy to be effective it is necessary for the light from the light box to enter the eyes indirectly. Just exposing the skin to the light does not have the same effect. Looking directly into the light can damage the eyes and is not advisable, except in a few patients who are asked to look into the light for brief moments before looking away again. However, sunglasses are not to be worn during light therapy as it blocks the light from entering the eye, adversely affecting the effectiveness of the therapy.
Light therapy is now considered a standard treatment for SAD. It offers numerous potential benefits for SAD sufferers especially for those who are averse to taking antidepressants or for those tried antidepressants and found them ineffective.
Understanding light therapy
Light therapy or bright light therapy is an effective method of treating seasonal affective disorder and has been in use since the 1980s. Light therapy is now considered standard treatment for SAD by mental health professionals all over the world.
A patient undergoing light therapy is required to sit in front of and facing a light box. A light box is a specially designed device that contains fluorescent tubes or bulbs, which emit a light that is similar to outdoor light. The key feature of light therapy is that it works only when the rays of light enter the body through the eyes. Merely exposing the skin or the rest of the body is basically ineffective and will not produce the desired results. However, looking directly into the source of light can cause considerable damage to the eyes. During light therapy it is important that the patient has their face slightly averted so that the rays of light can enter the retina without damaging the eyes in any way. The bulbs in the light box are also covered with a plastic screen that effectively blocks out harmful UV rays.
Undergoing light therapy is akin to sitting outdoors under the sun and causes similar biochemical reactions in the brain that work to relieve the symptoms of SAD and lift the patient’s mood. However, the light emitted by these bulbs is quite different in quality and intensity from that emitted in normal household bulbs, so sitting in front of a lamp in the living room cannot be used to replace light therapy.
Although light therapy boxes can be purchased over-the-counter without a prescription, as with any other medical treatment it is always advisable to get the advice of your doctor before you start.
Benefits of light therapy
Light therapy is especially beneficial for SAD sufferers who are averse to taking antidepressants either because they have been ineffective in the past or because they find the side effects of antidepressants intolerable.
It is also a good alternative for expectant women who are suffering from seasonal affective disorder but are reluctant to take antidepressants for fear of its effect on the developing fetus.
Light therapy is an affordable option for those individuals whose insurance policy does not cover mental health services.
Light therapy is helping in treating other conditions including obsessive, compulsive disorder, postpartum depression, premenstrual dysphoric disorder and other forms of depression besides seasonal affective disorder.
Individuals whose skin is sensitive to light or those who have an existing condition that sensitize their eyes to bright light may be advised not to opt for light therapy as a way to treat their condition. Light therapy is also not prescribed for individuals who take any kind of anti-inflammatory medication or antibiotics that react with sunlight.