Full Spectrum Light Therapy

Medically reviewed by Julie Dodson, MA
Updated June 4, 2024by BetterHelp Editorial Team

You may have heard of full spectrum light therapy before and wondered if it's something that can help you. Another kind of light therapy for depression, known as light box therapy, is also available and may be effective for treating a variety of conditions. When it comes to mental health, full spectrum light therapy is generally used to treat people who are experiencing seasonal affective disorder (SAD), but it may help those with other forms of depression as well.

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Light therapy can help ease depression

How does full spectrum SAD light therapy work?

When people are undergoing light therapy, they have a light therapy box that they use as their treatment. This box emits a light that a person stands or sits in front of.

Using a SAD lamp, which features a full spectrum light bulb, can be a great option for individuals who suffer from seasonal depression or are affected by shorter days. The light is designed to replicate the natural sunlight essential for a healthy lifestyle. When positioned in front of the lamp, you can close your eyes or leave them open, but avoid looking directly at the light. Note that this isn't an instant solution; however, with consistent use, you may notice an improvement in your depression symptoms and overall mental health.
Three essential components come into play when doing light therapy. The first is light intensity, known as lux, which indicates the amount of light received during therapy sessions. Many different types of lights are available, but for SAD (seasonal affective disorder), a standard 10,000 lux light is recommended when positioned between 16 and 24 inches away from it. However, for helpful information and guidance, it's advised to consult your doctor before purchasing a light, as they can provide specific recommendations based on your needs.
Other factors that can impact the effectiveness of your light therapy session are the duration and the timing. These are also factors that you can talk to your doctor or therapist about. Many people feel that it benefits them to do light therapy first thing in the morning. However, this is something that your therapist can help you determine for your particular situation. The duration of your therapy sessions depends on the type of light and the amount of lux.

The science behind light therapy suggests that consistency is an essential ingredient to its success. For shift workers or people with busy schedules, compact light therapy devices may be a great option. These devices can be used in a shorter amount of time and may have different types of light therapy, such as blue or red light therapy. However, it's important to consult with your doctor or therapist to determine the appropriate type and duration of full spectrum light therapy for your needs.

When did full spectrum SAD therapy become popular?

People have believed in the power of sunlight for healing for centuries. Natural light has been used as a medical treatment for as long as people can document. However, full spectrum light therapy boxes didn't start to become popular until the 1990s. Since then, the number of success stories from the use of light therapy has continued to keep it in the spotlight.

Who needs full spectrum SAD therapy?

Light therapy can be used to treat several different diseases and disorders, but for this article, we're going to focus on mental health. The people who can benefit the most from light therapy tend to be those who experience depression, especially seasonal affective disorder. However, it can also be used for other types of depression and to help people with circadian rhythm sleep disorders or those who travel frequently and experience jet lag.

Also, while blue light from screens can suppress melatonin (which helps with sleep), research has shown that exposure to blue light during the day can improve alertness.

The symptoms of seasonal affective disorder

The symptoms of SAD tend to be the same as those of other forms of depression. The main differentiator is that SAD typically occurs only during certain times of the year. For the majority of people, this will be during the winter (often referred to as the winter blues), but there are also people who experience it during a different season.

This means that the symptoms of SAD usually start around the same time every year and leave around the same time every year. It can work like a cycle, and it's something that you're able almost to predict.

Symptoms of depression may include feeling sad or down but can also include feeling angry and more irritable. You may experience changes in your sleeping pattern and in your desire to eat. Some people sleep more, but others sleep less. Similarly, some people eat more, but others eat less. Many people experiencing depression also start to withdraw from friends and family and the things that they enjoy in life. It can almost make them want to shut down.

Why can't we just go outside?

If full spectrum light therapy is really just giving people artificial sunlight, why can't they just go outside to take in actual sunlight? The best light is natural sunlight. However, in this day and age, there are many people who experience a shortage of the natural sunlight that they need. This could be people who work long hours and find themselves leaving for the office when it's dark in the morning and not leaving until it's dark at night. 

Full spectrum light therapy also comes into play for SAD in states that experience less sunlight during the winter months. Many people are affected by SAD between fall and early spring. This is because many states have more cloudy days in the winter, and when you combine that with shorter daylight hours, it can lead to depression for some people.

Unlike being outside where the amount of natural sunlight can vary, light therapy boxes can provide a consistent and controlled amount of light exposure for those who may not be able to get enough natural sunlight throughout the day.

How to get a SAD light therapy box

You can buy a SAD light therapy box online or in stores without having any type of a prescription. However, it’s still recommended that you talk to a doctor or therapist before getting one.

There are some adverse side effects that you can experience if you do not use a full spectrum light therapy box correctly. There are also some people who shouldn't use therapy boxes. Therefore, if you buy a light box without talking to a doctor first, you could see a decline in your health instead of the benefits that you’re looking for.

Light therapy boxes can range in price from $20 to thousands of dollars. This is another reason why you might want to talk to a professional before buying one. Buying the cheapest box may not be the best option for your mental health challenges, but you may not need to spend thousands on a box, either. 

Another factor that you might consider when purchasing a light therapy box is UV rays. There are many boxes available on the market that are UV free. The Verilux HappyLight, for example, mimics sunlight without UV rays, as does the Carex Day-Light Classic. The Carex Day-Light Classic has two light mode settings, allowing you to use it as a desk lamp when it’s not being used as a therapy light. Some therapy lamps, such as the Verilux HappyLight, come with a satisfaction guarantee.

If this all sounds a bit overwhelming, you may also find comparison guides helpful in making your selection. News outlets including The New York Times, The Huffington Post, and Good Housekeeping, among others, walk through the differences across makes and models offered by leading manufacturers.

Light therapy can help ease depression

What should I do if I think light therapy would work for me?

If you think that full spectrum light therapy is right for you, it may be helpful to consult with a therapist who specializes in or has experience with this type of treatment. They can provide guidance on the course of therapy that would be best for your specific needs.

During your initial therapy session, you can talk to the therapist about types of treatment that are available and tell them why you would like to try light therapy. They may give you their opinion on what treatment path will be right for you. For some people, light therapy is the only form of treatment that they need. However, other people also benefit from other forms of treatment, such as psychotherapy along with light therapy sessions.

Does this therapy work?

Some people are suspicious that light therapy can help with their depression. It's important that to remember that light therapy is not going to be the right option for everyone. It is not a cure-all for depression. However, some people experience significant results in improving their mental health and levels of depression through full spectrum light therapy.


If you are experiencing seasonal affective disorder (SAD) or the winter blues, light therapy could be the right option for you. However, you might also benefit from therapy. If you’re not feeling well enough to go to a therapist’s office, you might try online therapy, which research has shown to be just as effective as in-person therapy. With BetterHelp, you can contact your therapist from the comfort of your home via videoconference, phone, or in-app messaging. You can also be matched with a therapist experienced in SAD or depression. Take the first step and reach out to BetterHelp today.
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