Light therapy boxes can offer an effective treatment for seasonal affective disorder. Features such as light intensity, safety, cost and style are important considerations.

By Mayo Clinic Staff

Seasonal affective disorder (SAD) is a type of depression that typically occurs each year during fall and winter. Use of a light therapy box can offer relief. But for some people, light therapy may be more effective when combined with another SAD treatment, such as an antidepressant or psychological counseling (psychotherapy).

Light therapy boxes for SAD treatment are also known as light boxes, bright light therapy boxes and phototherapy boxes. All light therapy boxes for SAD treatment are designed do the same thing, but one may work better for you than another.

It's best to talk with your health care provider about choosing and using a light therapy box. If you're experiencing both SAD and bipolar disorder, the advisability and timing of using a light box should be carefully reviewed with your doctor. Increasing exposure too fast or using the light box for too long each time may induce manic symptoms if you have bipolar disorder.

If you have past or current eye problems such as glaucoma, cataracts or eye damage from diabetes, get advice from your eye doctor before starting light therapy.

A light therapy box mimics outdoor light. Researchers believe this type of light causes a chemical change in the brain that lifts your mood and eases other symptoms of SAD.

Generally, the light box should:

  • Provide an exposure to 10,000 lux of light
  • Emit as little UV light as possible

Typical recommendations include using the light box:

  • Within the first hour of waking up in the morning
  • For about 20 to 30 minutes
  • At a distance of about 16 to 24 inches (41 to 61 centimeters) from the face
  • With eyes open, but not looking directly at the light

Light boxes are designed to be safe and effective, but they aren't approved or regulated by the Food and Drug Administration (FDA) for SAD treatment, so it's important to understand your options.

You can buy a light box without a prescription. Your doctor may recommend a specific light box, but most health insurance plans do not cover the cost.

Here are some questions to think about when buying a light box for seasonal affective disorder (SAD):

  • Is the light box made specifically to treat SAD? If not, it may not help your depression. Some light therapy lamps are designed for skin disorders — not SAD or depression. The light boxes that treat skin disorders emit more ultraviolet (UV) light than the boxes that treat SAD, and they could damage your eyes if used incorrectly.
  • How bright is it? Brighter boxes will require less time to use each day, compared with dimmer boxes, to achieve the same effect. Look for a light box that provides the right intensity of light at a comfortable distance — ask your health care provider for recommendations.
  • How much UV light does it release? Light boxes for SAD should be designed to filter out most UV light. Look for a light box that emits as little UV light as possible. Contact the manufacturer for safety information if you have questions.
  • Does it use LEDs? Traditionally, light boxes have used fluorescent or incandescent lights. Some manufacturers now sell light boxes with light-emitting diodes (LEDs).
  • Does it emit blue light? Typically, light boxes use white light, but some light boxes give off blue light with a shorter wavelength. There is much more research available to support the use of bright white light to treat SAD than there is for blue light.
  • Can it cause eye damage? Although eye damage from using a light box is uncommon, blue light may pose a greater risk of harming your eyes than white light does. Check with the manufacturer if you have concerns about light box safety.
  • Is it the style you need? Some light boxes look like upright lamps, while others are small and rectangular. You can even buy a battery-powered light therapy device attached to a visor, but it isn't clear yet whether this type of light works as well as a standard light box. Because the effectiveness of a light box depends on daily use, it's important to buy one that is convenient for you.
  • Can you put it in the right location? Think about where you'll want to place your light box. Keep in mind that most boxes need to be within 2 feet (61 centimeters) of you.
  • Does your doctor recommend it? Talk to your health care professional about light box options. Doctors recommend that you be under the care of a health care provider while using light box therapy. If you are experiencing both SAD and bipolar disorder, the advisability and timing of using a light box should be carefully reviewed with your doctor.
March 16, 2016