Seasonal Depression (Seasonal Affective Disorder)
What Is Light Therapy for SAD?
Light therapy for SAD uses a full-spectrum bright light that is shined indirectly into your eyes. When you use light therapy, 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. It is important not to look directly at the light source of any light box for extended periods in order to minimize the risk of damage to your eyes.
Some people with SAD recover within days using light therapy. Others take much longer. If the SAD symptoms are not resolved, the prescribing doctor may increase the light therapy sessions to twice daily. Those who respond to light therapy are encouraged to continue until they can be out in the sunshine again in the springtime.
Does Light Therapy Work for Seasonal Depression?
Some researchers link seasonal depression to the natural hormone melatonin, which causes drowsiness. When light strikes the human retina, a process in the body decreases the secretion of melatonin. Light modifies the amount of melatonin in the human nervous system and boosts serotonin in the brain. So light therapy has an antidepressant effect.
Experts now believe that light therapy may be an effective treatment for people who have eating disorders, insomnia, and major depression (unrelated to SAD). Researchers have found that when depressed patients without SAD take antidepressants and use light therapy, there is an added benefit of increased energy and improved mood.
Can I Prevent Seasonal Affective Disorder?
If you have been diagnosed with seasonal affective disorder, here are some things you can do to help prevent it from coming back:
- Try to spend some amount of time outside every day, even when it's very cloudy. The effects of daylight are still beneficial.
- Begin using a light box when fall starts, even before you feel the effects of winter SAD.
- Eat a well-balanced diet, including sufficient amounts of vitamins and minerals as recommended by the FDA. This will help you have more energy even if your body is craving starchy and sweet foods.
- Try exercising for 30 minutes a day, three times a week.
- Stay involved with your social circle and regular activities. Social support is extremely important for those with mood disorders, especially during winter months.
When Should I Call my Doctor About Seasonal Depression?
If you experience feelings of depression, fatigue, and irritability that come at the same time each year and appear to be seasonal in nature, you may have a form of SAD. Talk openly with your doctor about your feelings. Follow the doctor's recommendations for lifestyle changes and/or treatment if you have SAD.
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 are expensive and health insurance companies do not usually cover them. While side effects are minimal with light therapy, be cautious if you have sensitive skin or a history of bipolar disorder.