How Does Light Therapy for Depression Work?

Depression can have a serious effect on the quality of your daily life. And, unfortunately, it affects a large number of people. The 2019 National Survey on Drug Use and Health found that more than 19 million adults in the U.S. dealt with at least one major depressive episode during the previous year. 

Most often, therapy and medication are used as the go-to treatments for depression. However, there are other, less known treatments that some people also try. One such treatment is light therapy. Though originally used to help with seasonal affective disorder (SAD), light treatment is also sometimes used for non-seasonal depression (like major depressive disorder and bipolar disorder). 

Learn more about this interesting approach and find out how effective it is. But first, to understand light therapy, you need to have a basic knowledge of depressive disorders.

Light therapy, sometimes called phototherapy, light treatment or bright light therapy, involves sitting near a light therapy box for a period of time (often 30 minutes). These light treatment boxes often use full-spectrum fluorescent lights. 

And there is some evidence it works. 

As we previously mentioned, light therapy is often used to treat seasonal affective disorder (SAD), which is a type of depression. SAD is characterized as significant changes in your mood in conjunction with changing seasons. It often starts in late fall or early winter months and lasts until spring. It’s thought that the days with less outdoor light can have a big effect on moods — or more specifically, the lack of exposure to light can lead to a depressive mood. 

While researcher’s don’t fully know what causes it, the thinking is that people with SAD may have reduced activity of the neurotransmitter serotonin (something sunlight can help boost).

A study published in the International Journal on Disability and Human Development looked at people with SAD and found that there were positive effects of bright light therapy after just 20 minutes, though 40 minutes was more optimal (over the course of many weeks). 

But bright light therapy may not just work for SAD. There’s some evidence published in The Journal of Biological and Medical Rhythm Research that says it could help with other types of depression, like major depressive disorder.

According to an article published in the journal, Frontiers in Psychology, light therapy is thought to work for depression because exposure to bright light at certain times of day can help align your circadian rhythm, balance the activation of serotonin, help establish stable sleep patterns and boost alertness.

While there are promising findings that light therapy can help non-seasonal depression, more research needs to be done before it can be stated that the effects of light therapy can help depression.

If you want to try bright light therapy for depression, go for it! There have been no harmful or negative side effects found associated with using this artificial light for different types of depression. Just know that it’s not guaranteed to work. 

If you’d prefer to stick to treatment approaches that have more evidence to support their efficacy, you’ll want to consider one of these options. 

Therapy

Cognitive-behavioral therapy (CBT), a type of talk therapy, has been found to be an effective way to treat the different types of depression, according to the Indian Journal of Psychiatry. 

In CBT, you’ll work closely with a therapist to identify what’s going on that may need to change, create goals of what you’d like to accomplish, and then identify patterns and behaviors that could be contributing to your depression and come up with ways to change them. 

Medication 

Prescription antidepressants are another effective treatment option for various types of depression. 

Antidepressants boost levels of certain neurotransmitters to help with depression. But they don’t work right away; it can take four to eight weeks before you may notice a difference in symptoms. 

Antidepressants often prescribed to treat depression include selective serotonin reuptake inhibitors (SSRIs) and serotonin–norepinephrine reuptake inhibitors (SNRIs). These work by addressing neurotransmitter deficiencies that could be causing your depression. SSRIs include citalopram, fluoxetine, and sertraline. SNRIs include duloxetine and venlafaxine. 

Bupropion (sold as the brand name Wellbutrin®) is another option. It is also used to treat seasonal affective disorder.

To recap, bright light therapy involves sitting near a light therapy box with full-spectrum fluorescent lights for a period of time (ideally 40 minutes per treatment session). 

This type of therapy has been shown to be an effective way of treating SAD (a form of depression that is sometimes called the winter blues) and there is promising research that shows that it may be beneficial for non-seasonal depression as well. This is because it can help restore your circadian rhythms, balance levels of serotonin and get you on a better sleep schedule. 

More research does need to be done to conclusively say that bright light therapy is a fully viable treatment option for depression when used at the right time of day. Thankfully, there are other treatment options that have been proven to be effective in their treatment of depression — namely therapy and medication. 

To figure out what treatments could help you navigate depression, it’s best to speak to a healthcare professional.