Light Therapy for SAD

The winter months may mean snowball fights, hot cocoa and holiday decorations, but they also mean less sunlight. And less sunlight can lead to seasonal affective disorder (SAD), which is now known as a major depressive disorder with a seasonal pattern.

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SAD is a form of depression that typically happens in the fall or winter. The lack of sunshine can affect your circadian rhythm, or your body’s internal clock, and throw your serotonin and melatonin levels out of balance. All of this can play a role in your sleep patterns and mood, making winter feel gloomy, both internally and externally.

Enter light therapy, which simulates sunlight to help treat SAD and other conditions like depression and sleep disorders. Psychologist Adam Borland, PsyD, talks about the science behind light therapy and how you can use it at home.

What is light therapy and what are light boxes?

Light therapy, also known as phototherapy or bright light therapy, uses artificial light to help treat SAD and other conditions that are associated with it. To use light therapy, you need to sit or work near a light therapy box for about 30 minutes.

“Especially in the winter, our bodies react to the gray, cold weather and lack of natural sunlight,” says Dr. Borland. “What light therapy does is compensate for the lack of exposure that we get from natural sunlight.”

There are light therapy options like dawn stimulators and natural spectrum light bulbs, but using a light box — a lamp-like device with a flat screen that uses full-spectrum fluorescent light — is most common in treating SAD.

“Look for one that gives an output of 2,500 to 10,000 lux, which is a way to measure light brightness,” Dr. Borland advises.

As you’re shopping for your light box, it’s worth noting that there are also specific colors of light therapy, like blue or red light therapy for skin health or green light therapy for migraines. But light boxes or other light therapy devices for treating SAD use a full-spectrum fluorescent light.

Does light therapy work for SAD?

Light therapy is considered the best treatment for SAD, combating some of the effects of winter darkness by helping your circadian rhythm and balancing your serotonin levels, as well as:

Improves depression: SAD is more common in people who already have depression. One study found that, whether it was used alone or with fluoxetine (an antidepressant medication), light therapy was effective in improving symptoms of depression.
Boosts the effectiveness of antidepressants: If you’re taking an antidepressant, consider using light therapy in partnership with your medications. “It helps balance and activate the serotonin in our brains,” Dr. Borland explains. “So, if someone is taking medication and engaging in talk therapy, all those things can help with mood.”
Aids sleep: If you have insomnia or circadian rhythm sleep disorders, light therapy can help by positively affecting melatonin and serotonin levels in your brain. It can also help you set up and keep an ideal sleep schedule.

In other words, yes, light therapy works for SAD, and it can help with SAD-adjacent concerns, too. But there’s a catch: Light therapy isn’t a one-and-done.

“To get the most effective and longest-lasting boost in your alertness, mood, energy and concentration, it’s important to use light therapy regularly,” Dr. Borland advises.

If you’re interested in using a light box, there are plenty of options available for purchase. With its affordable price point and small, convenient size, using a light box can be a great way to address your seasonal affective disorder.

How long should I use a light therapy lamp per day?

Dr. Borland says that while the amount of time you need to use your light box differs for everyone, most people use it for 20 to 30 minutes a day.

Be sure to read the manufacturer’s safety instructions for your device before getting started. But for the most part, here is the best way to use a light therapy lamp:

Use it in the morning. Dr. Borland recommends trying to use it as early in the day as possible. Using it at night can have negative effects on your sleep patterns.
Place it a short distance away. Put your light box on your desk or table, off to the side — usually about 16 to 24 inches away from you.
Don’t look directly into the light. You wouldn’t look directly into the sun, would you? (No!) “Use it just as a passive light source and don’t look into it directly,” he says.
Set a timer. Most light boxes come with a timer, but if yours doesn’t, set your phone alarm so you know when to hit the “off” switch. During that time, do whatever you’d normally do, like reading, eating breakfast or working on your computer.
Repeat daily. Use your light therapy lamp daily, if possible, until spring arrives and sunshine returns.

“Go in with an open mind,” Dr. Borland urges. “This is something that can be used in addition to medication, talk therapy, exercise and socializing — all of these things that are important in life.”