How big a role does sunlight exposure play in mood? Do light-therapy lamps really help depressed people feel better? If so, what type of light therapy should I look for?
Many people living in temperate climates report that they feel better during the transition from winter to spring, as the days grow longer and sunlight exposure increases. Conversely, a parallel drop in mood is often noted during the transition from fall to winter.
The potential therapeutic effects of bright (full-spectrum) white light have been evaluated in people with such winter depressions, and studies using appropriate control groups indicate significant benefit for these light treatments. The usual daily “dose” of light therapy is 30 minutes of exposure to 10,000 lux (a scientific measurement of the intensity of light) of full-spectrum light; some people do better with longer (60 to 120 minutes) periods of exposure.
It's not necessary to gaze directly into the light, but you should have your eyes open and sit within 3 feet of the light source. Several companies sell “light boxes” that have been developed to reliably deliver the correct dose; the typical cost is about $300. The easiest way to find a light box is to Google “light therapy for seasonal depression."
Learn more in the Everyday Health Depression Center.