How is seasonal affective disorder treated?

Research now shows that phototherapy, also known as bright light therapy, is an effective treatment for SAD. Sometimes antidepressant medicine is used alone or in combination with light therapy. Spending time outdoors during the day can be helpful, as well as increasing the amount of sunlight you're exposed to at home and in the office.

Cognitive-behavioral therapy (CBT) is a very effective psychotherapeutic approach to seasonal affective disorder. A recent study demonstrated that CBT produced the longest-lasting effects of any treatment approach.

What is light therapy? Is it safe?

Light therapy, sometimes called phototherapy, is provided by a device that contains white fluorescent light tubes covered with a plastic screen to block ultraviolet rays. The intensity of light emitted (Lux) should be 10,000 Lux. The patient does not need to look directly into the light, but reads or eats while sitting in front of the device at a distance of 2 to 3 feet.

Light therapy is generally safe and well-tolerated. However, there are some situations in which it cannot be used (for example, conditions such as diabetes or retinopathies, certain medications) because of the potential risk of damage to the retina of the eye. Bright light therapy can cause hypomanic or manic symptoms; therefore, individuals with bipolar affective disorder need to have medical supervision in order to use light therapy.

Side effects of light therapy include:

  • Eye strain
  • Headache
  • Irritability
  • Fatigue
  • Insomnia

At what time of the day should I use light therapy? For how long?

The timing of light therapy appears to affect the response. Recent studies suggest that morning light therapy is more effective than evening treatments. Using this treatment too late in the day may cause insomnia.

Many health professionals prefer to treat SAD with 10,000 Lux for 15 to 30 minutes every morning. Patients often see improvement within 2 to 4 days, and reach full benefits within 2 weeks. The symptoms of SAD return quickly after light therapy is stopped, so light treatment should be continued throughout the entire season of low sunlight.

Even though they generate enough light, tanning beds should not be used to treat SAD. The amount of ultraviolet (UV) rays they produce is harmful to the skin and eyes.

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