A woman writing next to a therapy lamp

Light Therapy for Seasonal Affective Disorder


There is evidence that patients who suffer from Seasonal Affective Disorder, or SAD, may benefit from exposure to artificial light through light therapy. This article will explore more about what SAD is, what light therapy is, and the benefits that light therapy offers patients who have SAD. 

What is Seasonal Affective Disorder?

Seasonal Affective Disorder, also known as SAD, is a form of depression. The symptoms usually begin in late fall/early winter and resolve during the spring/summer months. This is known as winter-pattern SAD. 

In some rare cases, the opposite is true: the symptoms begin in spring/summer and resolve in fall/winter. This is known as summer-pattern SAD. However, as mentioned, this form of SAD is much less common.

SAD is not a standalone disorder but a form of depression characterized by its seasonal pattern, with symptoms lasting 4 to 5 months each year. This means the signs/symptoms of SAD include those associated with major depression. Some particular symptoms differ for winter-pattern versus summer-pattern SAD. Also, keep in mind that not everyone will experience all of the symptoms mentioned below. 

A man standing on a mountain range in front of a blue sky

Symptoms of Major Depression

Following are some of the most common symptoms of major depression: 

  • Feeling depressed most of the day, most days
  • Loss of interest in activities 
  • Changes in appetite/weight
  • Problems with sleep
  • Feelings of sluggishness/agitation
  • Low energy levels
  • Feelings of hopelessness/worthlessness
  • Difficulty concentrating
  • Frequent thoughts of death/suicide

Symptoms of Winter-Pattern SAD

Some of the common symptoms specific to winter-pattern SAD include: 

  • Oversleeping
  • Overeating, particularly carbs
  • Weight gain
  • Social withdrawal

Symptoms of Summer-Pattern SAD

Some of the common symptoms specific to summer-pattern SAD include:

  • Difficulty sleeping
  • Poor appetite
  • Weight loss
  • Restlessness/agitation
  • Anxiety
  • Violent episodes of behavior

The Top Therapy Lamp for SAD


"Best for SAD. Designed to improve sleep, boost your mood, and improve concentration, it's highly recommended for individuals who experience SAD." - VeryWell Mind


What is Light Therapy?

Light therapy is also referred to as bright light therapy or phototherapy and is a form of therapy used to treat various mental health conditions. It is predominantly used to treat winter pattern SAD, which is also referred to as seasonal depression or winter blues. Light therapy is also beneficial for other forms of depression, sleep disorders, and a few other conditions.

This form of treatment gained recognition in the 1980s as a viable therapy. Since that time, it has become the first-line treatment for SAD. 

How Does it Work?

Light therapy is easy to use. You just need a light therapy lamp/box which you plug in, turn on, and sit close enough for your eyes and skin to absorb the light for a specified amount of time. The lamp/box is typically fluorescent light on a metal reflective base with a plastic screen to diffuse the light and filter out UV rays.

Individuals undergoing light therapy must get 10,000 lux of exposure to the light. At the proper distance, the better-quality lightboxes will allow more than 30 minutes of exposure. Don't look directly into the light during the entire session, as this could damage your eyes. Instead, allow your eyes to pick up the light indirectly. Ideally, you need to be 1.5 to 2 feet from the lamp/lightbox to get the most benefit.

The lightbox/lamp emits a bright light that simulates outdoor sunshine. This boosts your melatonin, vitamin D, and serotonin levels- as well as a few other positive effects.

However, you must make sure to check the recommendations from the manufacturer regarding how far you need to be from the light source to get an adequate amount of light within the specified period.

For example, if the instructions say that you should be 12 inches from the source for 30 minutes, and you’re sitting 24 inches away, you need to be exposed for 1 hour. If you have SAD, your physician will likely recommend that you begin treatment early in the fall and continue through the winter. You can take a break during late spring and summer.

It is believed that light exposure triggers the brain to produce serotonin, which is the "feel-good" hormone. This plays a critical part in the functioning of your mind/body and affects your sleep patterns, emotions, mood, and motor skills.

Exposure to light is also known to reset your circadian rhythm of melatonin. This is the reason why light therapy is also used to regulate the sleep/wake cycle.

Benefits of Light Therapy

The value of light therapy has been well-established, especially for use with SAD- but it’s important to understand that while this does offer improvement in symptoms, it is not a cure for the condition. The benefits provided by light therapy are short-lived and need to be maintained through consistent therapy.

Few Side Effects

One of the major benefits of using light therapy is that people have few to no side effects most of the time. If there are any side effects, there are not nearly as many as there might be with other forms of therapy. It's safe to use, and there are no contraindications with other forms of treatment.

However, it's important to note that photosensitive skin or eye conditions such as macular degeneration are not ideal candidates for light therapy.

As mentioned, there may be a few side effects, including headache, nausea, eyestrain, and irritability. However, these are typically minimal and will stop when you turn the device off or after a few days.

Additionally, moving away from the light source or shortening the duration of your treatment may decrease these issues. The typical course of treatment starts with 15 minutes and goes up from there.

Since it's not a medication-based treatment, it's safe for those who cannot or prefer not to take antidepressants. Light therapy is also an excellent option for augmenting or bridging treatment to offer additional relief while waiting on other kick-in methods.

Fast Results

Light therapy has been proven to provide results faster than other types of treatment- but that also means that if not used regularly, the effects will quickly wear off. Maximum effects are typically attained after several weeks of consistent use. However, most people will report feeling better after just a few sessions. 

Low Cost/Accessibility

After the initial investment of the device, which is typically covered by insurance, you don’t have any maintenance costs beyond the electricity to power the device. These devices are easily portable, which makes them convenient.

How to Know if Light Therapy is Right for You 

Talk with your healthcare provider about how a lightbox could benefit you and how it fits into other therapies you’re already using. Consider if you'll have the time or be willing to put effort into incorporating light therapy sessions into your day.

If you have been diagnosed with bipolar disorder, you'll want to speak with your medical provider about using light therapy because it could trigger a manic episode. Some studies indicate that light therapy is a viable treatment for bipolar, but more research is needed to confirm this.

How to Choose a Light Therapy Lamp

When you are choosing a light therapy lamp, there are several things that you must keep in mind:

  • Settings: Ideally, the lamp you choose should have adjustable dimming/brightness settings to allow for variety/versatility 
  • Shape: The lamp should fit with your environment and meet your needs: adjustable height, portability, sturdiness, other factors
  • Intensity of light: Typically, a light therapy lamp is 10,000 lux brightness- but there are other options available such as various settings/modes that allow for a gradual adjustment to daytime/nighttime. Additionally, there are several options for bulbs.
  • Timer: If your lamp has a built-in timer, you don’t have to worry about manually timing each of your sessions  


SAD, or seasonal affective disorder, is a form of depression that begins in the fall and continues through the winter. According to some experts, light therapy is a viable treatment option that can be used alone or with other treatment methods. There are only a few side effects, and it's very beneficial- but it does require some thought to get started.

Additional Light Therapy REsources

Sun graphic with text, The Ultimate Guide to Bright Light Therapy

The Ultimate Guide to Bright Light Therapy

A graphic of a woman sitting in front of a therapy lamp. Text, The ultimate guide to seasonal affective disorder

The Ultimate Guide to Seasonal Affective Disorder

Various light therapy lamps. Text, product quiz: selecting the right therapy lamp

Product Quiz: Selecting the Right Light Therapy Lamp

Sun and clouds graphic with text, What Happens if You Don’t Get Enough Sunlight?

What Happens if You Don't Get Enough Sunlight?


About the Author

Head shot for Brandon Landgraf

Brandon Landgraf is the Digital Marketing Manager for Carex Health Brands. He finds passion and fulfillment in creating content that enhances, improves, and enlivens others' quality of life. All of his written work is formulated to not only offer essential advice and tips but back it with proven studies and experts. His mission is to connect with readers and provide steps to make their lives better.

You can connect with him on LinkedIn here.

About Carex Health Brands

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Carex is your one-stop shop for home medical equipment and for products that assist caregivers with providing the best possible support and care for their loved ones. Carex Health Brands has been the branded leader in in-home, self-care medical products for over 35 years. Our goal is to improve the lives of our customers by bring them quality products that bring dignity back to their lives. With our three nationally distributed brands, Carex Health Brands serves national, regional and independent food, drug and mass retailers along with wholesalers, distributors and medical dealers.

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