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    Seasonal Depression (Seasonal Affective Disorder)

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    Light Therapy

    Some researchers link seasonal depression to the natural hormone melatonin, which causes drowsiness. Light changes the amount of melatonin in your nervous system and boosts serotonin in your brain. Light therapy has an antidepressant effect.

    A full-spectrum bright light shines indirectly into your eyes. You sit about 2 feet away from a bright light -- about 20 times brighter than normal room lighting. The therapy starts with one 10- to 15-minute session per day. Then the times increase to 30 to 45 minutes a day, depending on your response.

    Don't look directly at the light source of any light box for long times to avoid possible damage to your eyes.

    Some people with SAD recover within days of using light therapy. Others take much longer. If the SAD symptoms don't go away, your doctor may increase the light therapy sessions to twice daily.

    People who respond to light therapy are encouraged to continue it until they can be out in the sunshine again in the springtime. While side effects are minimal, be cautious if you have sensitive skin or a history of bipolar disorder.


    Spend some time outside every day, even when it's cloudy. The effects of daylight still help.

    Begin using a 10,000 lux light box when fall starts, even before you feel the effects of winter SAD.

    Eat a well-balanced diet. This will help you have more energy, even if you're craving starchy and sweet foods.

    Exercise for 30 minutes a day, five times a week.

    Stay involved with your social circle and regular activities. Social support is very important.

    When Should I Call my Doctor?

    If you feel depressed, fatigued, and irritable the same time each year, and these feelings seem to be seasonal in nature, you may have a form of SAD. Talk openly with your doctor about your feelings. Follow his recommendations for lifestyle changes and treatment.

    If your doctor recommends light therapy, ask if the practice provides light boxes for patients with SAD. You can also rent or purchase a light box, but they're expensive, and health insurance companies don't usually cover them.

    WebMD Medical Reference

    Reviewed by Joseph Goldberg, MD on April 25, 2016
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