Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get Started
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
What you can expect
By Mayo Clinic staff
Starting light therapy
The general recommendation for most people with seasonal affective disorder is to begin treatment with light therapy in the early fall, as soon as your symptoms start. Treatment generally continues until spring, when outdoor light alone is sufficient to sustain a good mood and higher energy.
Some people experience seasonal affective disorder in the summer. And others who typically have winter depression may notice symptoms during prolonged periods of cloudy or rainy weather during other seasons. You and your doctor can adjust your light box treatment based on the timing and duration of your symptoms.
For other conditions, talk to your doctor about the best time to begin light therapy.
During light therapy
During light therapy sessions, you sit or work near a light therapy box. To be effective, the light from the light box must enter your eyes indirectly. You can't get the same effect merely by exposing your skin to the light. While your eyes must be open, don't look directly at the light box because the light can damage your eyes.
Light therapy sessions are generally done each morning after you awake. Some light therapy boxes, however, are dawn simulators — they turn on in the morning while you're still asleep and gradually get brighter until you wake up.
Three key elements for effective light therapy
Light therapy is most effective when you have the proper combination of duration, timing and light intensity:
- Duration. When you first start light therapy, your doctor may recommend treatment for shorter blocks of time, such as 15 minutes. You gradually work up to longer periods. Eventually, your light therapy typically involves daily sessions ranging from 30 minutes to two hours, depending on your light box's intensity.
- Timing. For most people, light therapy is most effective if used in the morning, after you first wake up, rather than during the evening. Doing light therapy at night can disrupt your sleep. Because light therapy seems to work best in the early morning, you may need to wake up earlier than you normally would to match treatment with your natural biological rhythms. You may find it hard to wake up early, especially if depression leaves you feeling lethargic. Your doctor can help you find a light therapy schedule that works for you.
- Intensity. The intensity of the light box is recorded in lux, which is a measure of the amount of light you receive at a specific distance from a light source. Light boxes for light therapy usually produce between 2,500 lux and 10,000 lux, with 10,000 lux being typical. In contrast, the lighting in an average living room in the evening is less than 400 lux, while a bright sunny day may register 100,000 lux. The intensity of your light box may also determine how far you sit from it and the length of time you need to use it. The 10,000 lux light boxes usually require 30-minute sessions, while the 2,500 lux light boxes may require 2-hour sessions.
Finding time for light therapy
Light therapy requires time and consistency. You may be tempted to skip sessions or quit altogether because you don't want to spend time sitting by a light box. But light therapy doesn't have to be boring. It can be time well spent.
You can set your light box on a table or desk in your home or in your office. That enables you to read, use a computer, write, watch television, talk on the phone or eat while undergoing light therapy. Some light boxes are even available as visors that you can wear, although their effectiveness is still open to debate.
- Morgan AJ, et al. Self-help interventions for depressive disorders and depressive symptoms: A systematic review. Annals of General Psychiatry. 2008;7:13.
- Glickman G, et al. Light therapy for seasonal affective disorder with blue narrow-band light-emitting diodes (LEDs). Biological Psychiatry. 2006;59(6):502-507.
- Desan PH, et al. A controlled trial of the Litebook light-emitting diode (LED) light therapy device for treatment of seasonal affective disorder (SAD). BMC Psychiatry. 2007;7:38.
- Lurie SJ, et al. Seasonal affective disorder. American Family Physician. 2006;74(9): 1521-4.
- Byrne B, et al. Seasonal affective disorder and light therapy. Sleep Medicine Clinics. 2008;3:307-315.
- Even C, et al. Efficacy of light therapy in nonseasonal depression: A systematic review. Journal of Affective Disorders. 2008;108(1-2):11-23.
- Rosenthal NE. Winter Blues: Everything You Need to Know to Beat Seasonal Affective Disorder. Rev. ed. New York, N.Y.: Guilford Press; 2006:113-165.
