Solar Lamps & Depression

Light therapy is a method of treating symptoms of various depressive disorders, particularly seasonal affective disorder (SAD). Light therapy involves periodic exposure to a solar lamp, or light box that emits a bright light similar to sunlight. According to the Mayo Clinic, light therapy has not been approved by the Food and Drug Administration, though it is considered to be the main course of treatment for SAD. Although side effects are uncommon, there are some that are associated with the use of solar lamps to treat depression.

SAD

• Seasonal affective disorder is characterized by symptoms of depression that recur as the seasons change each year. According to the National Alliance on Mental Illness (NAMI), most cases of seasonal affective disorder involve symptoms that recur in the winter when there is less available natural light. Some people may experience seasonal depression in the summer, but this is rare, according to the NAMI. Symptoms of SAD that recur in the winter may include persistent feelings of sadness, sleeping more than usual, fatigue, withdrawal from social situations and diminished interest in enjoyable activities.

Types

• According to the Mayo Clinic, light therapy may treat types of depression other than seasonal affective disorder, including postpartum depression. Light therapy may also help to treat obsessive-compulsive disorder (OCD), which is a type of anxiety disorder, and premenstrual dysphoric disorder.

Phototherapy

• Also known as phototherapy, light therapy involves daily exposure to a specialized solar lamp or light box that emits white light. "Full spectrum" light bulbs may not be sufficient to have healing effects. According to NAMI, 50 to 80 percent of those who undergo light therapy for seasonal affective disorder may experience a reversal of their depressive symptoms. Treating some cases of depression may require a combination of antidepressant medications and light therapy.

Considerations

• There are many solar lamps and light boxes available for purchase. According to the Center for Environmental Therapeutics (CET), any solar lamp or light box used to treat depression should be able to "provide 10,000 lux of illumination" as well as filter out ultraviolet rays, exposure to which can damage the skin and eyes. CET also recommends purchasing a solar lamp or light box that has been "tested successfully in peer-reviewed clinical trials."

Dosage

• When using a solar lamp to treat depression, in addition to providing the required 10,000 lux of light, the lamp should be placed at eye level or slightly above. A phototherapy session last 20 minutes to an hour daily, depending on the severity of depressive symptoms. According to NAMI, "most patients" with seasonal affective disorder may receive the greatest benefit from phototherapy in the morning, which may help to regulate a person's "internal circadian rhythm clock."

Side Effects

• According to NAMI, side effects of light therapy are rare, and there is no evidence that light therapy causes "long-term adverse effects." Side effects may include nausea, headaches and irritability. Light therapy may cause mania in people who have some form of bipolar disorder and people whose seasonal affective disorder involves hypomanic or manic episodes. Such people may need to supplement their light therapy with a mood-stabilizing medication.