Those who suffer from seasonal affective disorder, or “winter blues,” during darker months of the year may soon see a glimmer of light at the end of this gloomy tunnel.

Scientists have found that exposure to specific wavelengths of light early in the morning can be an effective solution to winter depression. When Halloween candy and holiday cheer can’t do the trick, bright light therapy can bring brightness — literally and figuratively — to those who feel depressed when daylight is scarce.

According to the American Academy of Family Physicians, an estimated 4to 6percent of Americans will suffer from seasonal depression starting around this time of year, and another 10 to 20 percent will experience mild symptoms including low energy, poor concentration, disrupted sleep and withdrawal from social activities. Up to 35 percent of those affected by these symptoms need to be hospitalized, but the danger can be minimized by treatment with wide-spectrum, bright light for 15minutes immediately after waking. Patients using this treatment report increased energy, concentration and mood stability, as well as better eating habits and a more regular sleep cycle.

The relationship between light exposure and mood is grounded in human nature. Seasonal depression results from excessive nocturnal secretion of melatonin, a hormone that regulates the circadian rhythm, during the darker months of the year. This overabundance causes behaivors that decrease energy use, such as sleep and depression. These winter blues are believed to be an evolutionary adaptation to decrease caloric intake and increase survival rates during the cold season when, historically, food was scarce. Using artificial sunlight to cure SAD works because the bright light mimics sunlight, fooling the body into responding as if it is summertime.

Because SAD is a response to an external stimulus, it makes sense to cure it with a nonchemical, counteracting stimulus: light itself. In addition to its natural composition and lack of sideeffects, bright light therapy outshines drug treatments in other ways. While pharmaceutical remedies such as selective serotonin reuptake inhibitorscan take up to six weeks to see effect, light therapy provides benefit after only four to six days of treatment. Furthermore, the use of light has been seen to increase production of vitamin D, which is negatively correlated to depressive symptoms. The only problem with bright light therapy is that it only succeeds in two-thirds of the cases that SSRIs do, but the numerous ancillary long-term benefits of natural treatment may make it worth it.

The ancient Greeks were right to worship the sun god for their well-being; light therapy is known to have many health benefits outside of curing SAD. The remedy has proven effective in patients with nonseasonal psychiatric disorders like major depression, bipolar disorder and postpartum depression. Perhaps the most significant application of bright light therapy, however, is in alleviating sleep disorders such as insomnia, jet lag and sleep cycle disruptions. For dementia patients and children with severe mental retardation, exposure to bright light corrects their irregular sleep-wake rhythms. Even for people who don’t have a sleep problem, the harmless treatment can provide increased energy, alertness and focus on tasks.

Light therapy is used to manage numerous other common ailments, including psoriasis, chronic pain, hair loss, poor blood circulation and sinus-related diseases. In elderly Parkinson’s disease patients, light therapy can reduce hand tremors. Treatmentwith light from light-emitting diodes can cure the painful mouth sores that chemotherapy can cause in cancer patients,bright light therapy device, you might find yourself singing carols long after Christmas has passed.