Does Light Therapy Really Work for SAD?

Seasonal Affective Disorder (SAD) is a type of depression that typically starts in the fall and continues throughout the winter months. It affects about 5 percent of people in the United States annually and can be quite debilitating, causing feelings of sadness, low energy and apathy.

Evidence suggests that light therapy, also known as phototherapy, can be an effective treatment for this condition. Read on to find out how light therapy works and how you can use it to combat SAD.

Related: 5 Natural Remedies for SAD

How Does Light Therapy Work?

Light therapy consists of sitting close to a device called a light therapy box, which gives off light that mimics natural sunlight. You can work, read or eat as you receive the therapy.

More research is needed to determine the exact biology behind light therapy, but itís known that exposure to light boosts certain hormones in your body that help regulate mood. Researchers believe this is one of the ways light therapy can help reduce depressive symptoms.

Is It Really Effective?

The American Journal of Psychiatry published a review of studies on light therapy for treating mood disorders. The reviewers noted that there is limited funding available for light therapy research, which means many studies are often small and inconclusive. But they found 20 high-quality studies that they included in the review.

Overall, the studies found a significant improvement in SAD symptoms when people received light therapy. They estimated that light therapy can help in 80 percent of all SAD cases, and it can be equally as effective as treatment with certain antidepressants.

Interestingly, light therapy is also shown to benefit nonseasonal depression. The benefits arenít quite as pronounced as for SAD, but they are equally as effective as treatment with pharmaceutical antidepressants.

Research so far has been positive. However, the best experiment is to try light therapy on yourself and see how effective it is for you.

How to Find a Good Light Therapy Box

Many different types of light therapy boxes are available online or at pharmacies and other stores. Make sure a light therapy box meets the standards below before you buy one.

You donít need a prescription to buy a light therapy box, but speak to your doctor before getting one to discuss their recommendations and any possible side effects.


The best results for SAD have been shown with light therapy boxes that emit 10,000 lux (lux is a measurement of light intensity). By comparison, lights in your home typically emit around 50 lux. These are not strong enough to provide adequate light for therapeutic purposes. Full-spectrum light bulbs are also inadequate.

So, look for light therapy boxes rated at 10,000 lux. Boxes that emit less light can still be used, but youíll likely need longer exposure times.

Light Quality

Itís important to find light boxes that emit full-spectrum, white light. Some lights have come on the market that emit blue light, but these are unproven and should be avoided until supporting research has been done.

Low Ultraviolet Light

Ensure your light therapy box filters out as much ultraviolet (UV) light as possible. UV light can cause skin and eye damage.


Light therapy boxes come in a variety of shapes and sizes. When youíre shopping for one, consider where youíre going to put it so you can get one that will fit your space.

Dawn Simulation Devices

Research has shown that dawn simulation devices are also effective for treating SAD, as long as they meet the same standards as light therapy boxes as described above. Dawn simulation devices are similar to light boxes, but they can be set on a timer to gradually increase their light intensity as would naturally happen at sunrise. They are often sold as alternatives to alarm clocks.

Tips for Light Therapy at Home

Expose Yourself

For best results, light from the light box must enter your eyes indirectly. Itís ideal to have the light box close to you on a desk or table in your home or office. This allows you to read, watch TV, talk on the phone or do other activities while receiving therapy. Position your light box about 16 to 24 inches (41 to 61 centimeters) from your face.

Keep your eyes open, but donít ever look directly at the light box. The bright light can damage your eyes.

Give Yourself Enough Time

Studies have found that sitting in front of a 10,000-lux light box for 30 minutes every day is an effective dosage of light therapy for the majority of people. Although, some people may only need 15 minutes per day to get good results. Whereas, others may do better with 1-hour sessions.

To determine whatís best for you, start with the recommended 30-minute sessions for one week and evaluate how you feel at the end of the week. If it seems like too much or not enough, adjust your session time accordingly and try again for another week to see the results.

Be Consistent

When you use light therapy daily, SAD symptoms often improve within a week. Although, symptoms generally return if light therapy is reduced or stopped. This is why itís important to maintain a daily schedule at first. Once youíre feeling better, you can experiment with less frequent therapy and see how you respond. If you have a relapse of symptoms, go back to daily therapy.

Most users start light therapy in fall or winter once SAD symptoms start, and continue until spring when outdoor light levels are enough to sustain a positive mood and higher energy levels.

Start Early in the Day

Light therapy is best done within the first hour of waking up in the morning, preferably while itís still dark outside. This helps to trick your body into believing the days are longer than they really are, and encourage your hormones to adjust accordingly.

Dawn simulation devices may be helpful for this, as you can set them to start brightening while youíre still asleep and then wake up to an illuminated room.

Do Not Use Tanning Beds

Tanning beds are shown to be ineffective for helping SAD. They also expose you to potentially damaging levels of UV light that can increase your risk of skin cancer.

Related at Care2



John B
John B25 days ago

Tanks Zoe for sharing the info.

Jerome S
Jerome Sabout a month ago


Jerome S
Jerome Sabout a month ago


Jim V
Jim Venabout a month ago

thanks for sharing

Jim V
Jim Venabout a month ago

thanks for sharing

Dave f
DAVID fleming3 months ago

proven that people are more happy in summer than in winter so it must have some point

sharon b
sharon b3 months ago

My doctor is recommending it

heather g
heather g3 months ago

Canada is so far north that we should all use light therapy.

Just Human
Just Human3 months ago

Light therapy didn't help me unfortunately. What did work was exercise.

Joan E
Joan E3 months ago

Sorry to hear that it isn't being used any more in Belgium, as it seems to help many people.