David Baxter PhD
Late Founder
Light therapy
By Mayo Clinic Staff
Oct. 7, 2008
Light therapy is a way to treat seasonal affective disorder, depression and certain other conditions by exposure to bright artificial light. During light therapy, you sit or work near a device called a light therapy box. The light therapy box gives off bright light that mimics natural outdoor light.
Exposure to bright light from a light therapy box is thought to alter your circadian rhythms and suppress your body's natural release of melatonin. Together, these cause biochemical changes in your brain that help reduce or control symptoms of seasonal affective disorder and other conditions. Light therapy is also known as bright light therapy or phototherapy.
Why it's done
Light therapy is one of the many ways to treat a variety of mental disorders and conditions affected by time changes or shift changes, especially seasonal affective disorder. The light box used in light therapy emits a type and intensity of light that isn't found in normal household lighting. So simply sitting in front of a lamp in your living room is unlikely to relieve your seasonal affective disorder symptoms or other problems.
Similarly, a light box delivers brighter, more focused light than you can find outdoors, which makes it more effective than trying to get enough light exposure by spending time outside ? especially on gloomy days.
When to consider light therapy
Light therapy may be a treatment option for you if:
Conditions and problems that may benefit from light therapy include:
Risks
Risks and side effects associated with light therapy are uncommon but can happen. They can include:
Who shouldn't use light therapy
Some light boxes don't filter out or shield harmful ultraviolet (UV) light. UV light can cause skin and eye damage. Don't use light therapy without consulting your doctor first if:
Light therapy may trigger episodes of mania in people with bipolar disorder. Also, although rare, some people, particularly those with severe forms of depression, develop thoughts of suicide after light therapy. Be sure to talk to your doctor or mental health provider before starting light therapy or at any time during treatment if your condition gets worse.
How you prepare
You don't need any special preparation to have light therapy. Before starting light therapy, however, check with your doctor and mental health provider to make sure it's a good option for you.
Your doctor or mental health provider also can help you choose an appropriate light therapy box. Internet retailers, drugstores and even some hardware stores offer a wide variety of light therapy boxes and other light devices for seasonal affective disorder treatment. Be sure to familiarize yourself with the variety of features and options to help ensure that you buy a light therapy box that's safe and effective for you.
What you can expect
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:
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.
Results
Light therapy probably won't cure seasonal affective disorder, depression or other conditions. But with safe and effective light therapy, your symptoms can get better. You may feel better about yourself and life again, and have more energy.
Light therapy can start to improve symptoms within just a few days. In some cases, though, it can take two or more weeks.
Getting the most out of light therapy
Light therapy isn't effective for everyone. But you can take steps to get the most out of your light therapy and help make it a success, including:
By Mayo Clinic Staff
Oct. 7, 2008
Light therapy is a way to treat seasonal affective disorder, depression and certain other conditions by exposure to bright artificial light. During light therapy, you sit or work near a device called a light therapy box. The light therapy box gives off bright light that mimics natural outdoor light.
Exposure to bright light from a light therapy box is thought to alter your circadian rhythms and suppress your body's natural release of melatonin. Together, these cause biochemical changes in your brain that help reduce or control symptoms of seasonal affective disorder and other conditions. Light therapy is also known as bright light therapy or phototherapy.
Why it's done
Light therapy is one of the many ways to treat a variety of mental disorders and conditions affected by time changes or shift changes, especially seasonal affective disorder. The light box used in light therapy emits a type and intensity of light that isn't found in normal household lighting. So simply sitting in front of a lamp in your living room is unlikely to relieve your seasonal affective disorder symptoms or other problems.
Similarly, a light box delivers brighter, more focused light than you can find outdoors, which makes it more effective than trying to get enough light exposure by spending time outside ? especially on gloomy days.
When to consider light therapy
Light therapy may be a treatment option for you if:
- You don't want to take medications such as antidepressants
- You can't tolerate the side effects of antidepressants
- You've tried antidepressants but they haven't been effective
- You want an alternative to psychotherapy
- You're pregnant or breast-feeding and are concerned about the effects of antidepressants on your developing fetus or baby
- You don't have insurance coverage for mental health services
- You lack access to mental health services
Conditions and problems that may benefit from light therapy include:
- Seasonal affective disorder
- Nonseasonal types of depression
- Obsessive-compulsive disorder
- Premenstrual dysphoric disorder
- Postpartum depression
- Jet lag
- Certain sleep disorders
- Shift-work problems
Risks
Risks and side effects associated with light therapy are uncommon but can happen. They can include:
- Eyestrain
- Headache
- Agitation
- Nausea
- Vomiting
- Irritability
- Fatigue
- Dry mouth
- Sleep problems
- Mania
Who shouldn't use light therapy
Some light boxes don't filter out or shield harmful ultraviolet (UV) light. UV light can cause skin and eye damage. Don't use light therapy without consulting your doctor first if:
- Your skin is sensitive to light
- You take medications that react with sunlight, such as certain antibiotics or anti-inflammatories
- You have an eye condition that makes your eyes vulnerable to light damage
Light therapy may trigger episodes of mania in people with bipolar disorder. Also, although rare, some people, particularly those with severe forms of depression, develop thoughts of suicide after light therapy. Be sure to talk to your doctor or mental health provider before starting light therapy or at any time during treatment if your condition gets worse.
How you prepare
You don't need any special preparation to have light therapy. Before starting light therapy, however, check with your doctor and mental health provider to make sure it's a good option for you.
Your doctor or mental health provider also can help you choose an appropriate light therapy box. Internet retailers, drugstores and even some hardware stores offer a wide variety of light therapy boxes and other light devices for seasonal affective disorder treatment. Be sure to familiarize yourself with the variety of features and options to help ensure that you buy a light therapy box that's safe and effective for you.
What you can expect
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.
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.
Results
Light therapy probably won't cure seasonal affective disorder, depression or other conditions. But with safe and effective light therapy, your symptoms can get better. You may feel better about yourself and life again, and have more energy.
Light therapy can start to improve symptoms within just a few days. In some cases, though, it can take two or more weeks.
Getting the most out of light therapy
Light therapy isn't effective for everyone. But you can take steps to get the most out of your light therapy and help make it a success, including:
- Be consistent. Sticking to a consistent daily routine of light therapy sessions can help ensure that you maintain improvements over time. If you simply can't do light therapy every day, take a day or two off, but monitor your mood and other symptoms ? you may have to find a way to fit in light therapy every day.
- Time it right. If you interrupt light therapy during the winter months or stop too soon in the spring when you think you're improving, your symptoms could return.
- Check your light box. Make sure your light box is intended to treat seasonal affective disorder or your specific condition. Light boxes that aren't specifically designed to treat seasonal affective disorder may not have the appropriate brightness or safety features.
- Consider LEDs. Some newer light boxes use light-emitting diodes (LEDs) instead of the more traditional fluorescent or incandescent light bulbs. Some evidence shows that LED light boxes emit more focused light and may be more effective.
- Include other treatment. If your symptoms don't improve enough, you may need additional treatment along with light therapy. Talk to your doctor about other treatment options, such as psychotherapy or antidepressants.
