Do Sun Lamps Actually Work? Seasonal Affective Disorder (SAD)

During World War I, physicians noted that wounds healed faster in patients who were exposed to sunlight. As starvation and malnutrition hit the population, children developed rickets, caused by poor diet and lack of sunlight.

Kurt Huldschinsky, a Berlin physician, discovered that ultraviolet light from lamps effectively treated rickets. Gradually, the use of sun lamps was extended to treat skin disorders, burns, sleep disorders, neonatal jaundice, and even some psychiatric disorders.

The sun lamp should be placed at a good distance from where a person works or sits. They need to have their eyes open, but should not stare at the lamp because the light may damage the eyes. 

An effective sun lamp should have a minimum intensity of 2,500 lux. However, the most prescribed sun lamp is of 10,000 lux intensity, which is to be used in the morning. Sun lamps are mostly used in the fall because, during this season, the intensity of natural sunlight is low.

Light therapy depends on what it is being used for, and accordingly, the session is either done in the morning or evening. To treat vitamin D deficiency, light therapy is given early in the morning for 15 minutes. To treat seasonal affective disorder, light therapy is administered for a couple of hours in the morning, evening, and night. The time and intensity of the light used is prescribed by a doctor depending on the condition of the patient.

The exact mechanism behind the therapeutic benefits of sub lamps is not completely understood. Exposure to light may affect levels of hormones, such as melatonin and serotonin, which regulate mood and sleep. Vitamin D production and a decrease in blood pressure are seen with exposure to natural ultraviolet rays in sunlight, so it is believed that ultraviolet rays from sun lamps may have the same effect on the body.

While light therapy is generally safe, exposure to ultraviolet rays come with risks:

• Patients who are on medications that cause photosensitivity, such as hormonal medications, acne medications, and skin peels, could be at risk of damaging their skin or eyes.
• Patients with bipolar disorder may have an increased risk of developing manic symptoms.
• Patients who are sensitive to light may be at risk of developing skin cancers.
• During the initial stages, the therapy may cause nausea, headache, and eye strain, although these symptoms typically resolve after a week.
• The FDA has issued a warning that sunlamp products should not be used on people younger than 18 because of the associated risks of eye damage, premature skin aging, and cancers.