What is Seasonal Affective Disorder?
Seasonal Affective Disorder (SAD) is a combination of body and mood disturbances that occurs in a seasonal pattern, beginning usually in the fall and winter and lessening in the spring or summer. SAD is a serious health problem due to its repeated recurrence and long duration. Left untreated, symptoms can significantly impact your well-being, family, and productivity.
Studies estimate that SAD affects up to 10 percent of the population in northern latitudes. In any given year, approximately 5 percent of the U.S. population is affected by SAD, with symptoms lasting as long as 40 percent of the year. It affects higher numbers of women than men, particularly during childbearing years, but also affects older children beginning around 16 years of age. Patients living in northern latitudes are considered to be at higher risk due to the shortening of daylight hours.
Although the specific physiological mechanisms leading to SAD remain uncertain, a generally accepted factor is the disruption to your body’s internal clock caused by the reduced level of sunlight in the fall and winter months. It is important to take steps to improve your mood and energy, since ignoring signs as simply a case of the “winter blues” or a seasonal funk can lead to worsening symptoms.
Light Therapy Treatment for SAD
Light therapy is widely accepted as an effective first line treatment in most people in relieving SAD symptoms. In light therapy, a special light box exposes you to bright, full-spectrum light, ideally every day within the first hour of waking up. The bright, expansive light in an effective substitute for natural sunlight. A change in mood-regulating brain chemicals results. The effectiveness of light therapy generally begins in a few days to a few weeks. However, as many people experience the return of symptoms when abruptly discontinuing light therapy, usage should continue until spring or summer with daily usage time slowly tapering off.
Although light therapy is occasionally accompanied by side effects including headache, eye strain, and nausea in some users, these effects are usually mild and temporary. There is no evidence that supports light therapy as causing ocular or retinal damage. However, users with preexisting retinal disease, bipolar disorder, or who are taking photosensitizing medication should consult with their doctor before beginning light therapy.
It is best to consult with your health care provider about choosing and using the right light therapy lamp for you. If you are experiencing both SAD and bipolar disorder, you should review with your doctor the advisability and timing of undergoing light therapy.
According to the Mayo Clinic, a good light therapy lamp should provide an exposure to 10,000 lux of light and should emit as little or no UV light as possible. Therapy lamps can be purchased without a prescription but the cost is generally not covered by most health insurance plans.
It is important that the light therapy lamp you choose be specifically designed to treat SAD. Some types of lamps are meant for treating skin disorders and could emit eye-damaging UV rays. A brighter light therapy device would require less time to use than one that is smaller and dimmer.
Also check out our usage guide and tips for light therapy.