Health Benefits Of Seasonal Affective Disorder (SAD) Light Therapy

Seasonal affective disorder (SAD) light therapy

Seasonal affective disorder (SAD) is a type of depression that coincides with the change of seasons. The National Center for Complementary and Integrative Health defines it as, “ a type of depression with a recurring seasonal pattern.” While many people with SAD experience symptoms during the fall and winter months, some may develop this disorder during the spring and summer. SAD usually causes typical depressive symptoms, similar to other mood disorders, such as excessive sleeping, mood swings, feelings of sadness and hopelessness, and low energy. However, light box therapy can be an effective treatment for SAD by helping to control the body's circadian rhythm and improve mood.

Seasonal affective disorder light therapy offering symptom relief

While both psychotherapy and medication may be used as interventions for SAD, the first line of treatment prescribed by clinicians is typically phototherapy, or light therapy, which is a simple and non-invasive form of treatment. According to the New England Journal of Medicine, “Human diseases have been treated with the sun's rays since antiquity.” For many people, light boxes relieve their symptoms of depression quickly without the need for medication or other additional treatment. The most common tool used for light therapy is a light source called a light box or “SAD lamp”. Light boxes emit a specific type of bright light to mimic outdoor light and can be used daily in your home to offer relief from symptoms. Read on to learn about starting light therapy and the potential benefits of a light box for seasonal affective disorder.

What causes seasonal affective disorder (SAD)?

Shorter days during the winter months can produce symptoms of depression for some people, but SAD can occur during any season including summer. As the seasons change from summer to fall, the days get shorter and the amount of exposure we get to the light of the sun decreases. For some people, these changes can lead to a series of mood-related symptoms, such as feelings of sadness and hopelessness, lethargy, carbohydrate cravings, and excessive sleeping. People who are experiencing SAD may also experience weight gain during the winter months. These symptoms may indicate that a person is experiencing SAD, or seasonal affective disorder. For those with summer SAD, it may actually be the extended exposure to sunlight that leads to these symptoms.

While researchers are still trying to understand why this disorder develops, studies have revealed that a lack of exposure to sunlight can disturb the patterns of a person’s circadian rhythm—or the natural, internal process that manages our sleep patterns. In turn, this disruption can affect serotonin and melatonin levels in the brain. Both of these are important neurotransmitters that play a pivotal role in managing sleep and mood. 

Why bright light therapy works for seasonal affective disorder (SAD)

A therapeutic light box can help alleviate symptoms of the seasonal affective disorder by mimicking natural sunlight. Research suggests that light therapy for depression enhances mood by helping align a person’s sleep-wake cycle and balancing serotonin activity within the brain.

Treatment of choice for seasonal affective disorder (SAD)

While antidepressants, psychotherapy, and lifestyle changes, among other tactics like sunrise alarm clocks, may also be recommended for those experiencing SAD, light therapy is typically the first line of defense. The Center for Environmental Therapeutics describes it as the “treatment of choice” for seasonal depression. More research has yet to be done on how this therapy works, but clinical trials have shown that patients can have an improvement in their SAD symptoms after as little as two weeks after beginning treatment.

Note that per an article from the University of Saskatchewan’s College of Medicine, light therapy can be effective for treating SAD during winter months. However, the article also says that seeking additional treatment from a mental health professional for symptoms that persist year-round is recommended, since SAD may actually be clinical depression that’s intensified in certain seasons.

Harvard Medical School recently published a 2022 study exploring whether or not this treatment could be beneficial for other mental health conditions beyond just SAD. The study found that light therapy could be beneficial in treating symptoms of major depression and other mental health conditions.

Risks of treatment

One of the major benefits of light therapy lamps is that they have minimal risks and side effects. Some patients, such as the elderly or pregnant people, may need to avoid medications, and the light produced from these lamps can help to improve SAD symptoms without the use of medications.

Although light therapy is considered generally safe, there can also be risks associated with it, which can be important considerations before beginning treatment. People with bipolar disorder should use caution and consult with their physician because, in severe cases, increased light exposure from light therapy could trigger a manic episode. Some commercially available phototherapy devices may also use ultraviolet radiation (UV lights), which could lead to skin conditions (such as redness or dry skin) or skin cancer. And in all cases, those pursuing this type of treatment should maintain a proper distance from SAD lamps and follow the manufacturer's instructions.

How therapy lux light boxes work

A light box or visor (a portable, head-mounted light) is typically used for phototherapy. All the individual has to do is sit near the box or wear the visor and naturally absorb the bright light it emits. These devices typically provide exposure to 10,000 lux of light (the standardized measurement of light levels)—usually LED light while also emitting a small, safe amount of UV light. The light intensity of the light box should be at a safe level to avoid eye damage. For many people and with regular, proper use, this emitted light is enough to reinstate a healthy circadian rhythm and adequate levels of serotonin and melatonin in the brain.

When should I use the SAD light therapy lamp?

It’s important to use these therapeutic lamps in the morning only to get the full effect, since using it later in the day or at night can negatively impact your sleep. As little as 20–30 minutes of light box treatment per day can meaningfully reduce symptoms of SAD in as little as a few days or a couple of weeks in some cases. 

The physical characteristics of the light may also play a role in its uses. Using a phototherapy light box with a red hue before bed might have benefits for reducing the effects of blue light on the circadian rhythm. Red light box treatment is a form of phototherapy that focuses on how colored light impacts the brain. Blue light from watching TV, working on the computer, and looking at smartphones can cause eye strain and interrupt sleep patterns. Irregular sleep can be a symptom of SAD and nonseasonal depression, such as major depression, that red light therapy may help.

One research study tested the effects of red light therapy on athletes over several weeks. The study found that a half hour of red light before bed improved sleep quality and increased melatonin production. Improving melatonin production can be beneficial for getting a better night’s sleep.

Choosing and using light boxes

This is especially true if you have certain conditions like glaucoma, cataracts, a history of lupus, or sensitivity to sunlight, any of which could be exacerbated by use of a light box.

If your doctor or psychologist has recommended you use a light box, there are a few things to take into account when selecting and operating one. First, make sure that your box was explicitly built for treating SAD. Some boxes are created for skin disorders, for instance—which could not only be ineffective in treating this disorder, but could damage your eyes. If you’re unsure about which light box might be best for you, ask a qualified healthcare provider for a suggestion.

Follow the instructions

Make sure to follow the instructions that come with the unit, along with any tips from the health professional who recommended it to you like keeping the light at a safe distance from your eyes and using the recommended settings. Common safety precautions include:

• Keep the light box 16–24 inches away from your face
• Keep your eyes open, but do not look directly into the light
• Do your best to remain relaxed and avoid stress while using the box
• Avoid blue light from nearby TV or phone screens during use
• Contact your doctor if you experience side effects

There are a variety of features to consider when shopping for the best light therapy lamp such as the size, light intensity, and controls. Choosing the right kind of lightbox will help you to ensure that you are receiving the maximum effectiveness from the SAD treatment. Smaller lightboxes can be used for traveling so that patients can treat SAD the same way regardless of where they are located. Some light boxes have multiple color settings for imitating different times of the day.

Other types of therapeutic treatment to consider for mental health

However, phototherapy is not a replacement for psychotherapy or other recommended treatments for certain mental health conditions. It’s possible that symptoms of SAD can worsen symptoms of a broader depressive disorder, which will typically not resolve without professional treatment. If you suspect you may be experiencing some form of depression or another mental illness, it may be wise to consult with a mental health professional for an evaluation. 

People with depression may sometimes have trouble finding the energy to attend in-person appointments on a regular basis. For situations like these, or those where the individual simply prefers to speak with a provider from the comfort of their own home, online therapy is a viable alternative to in-office sessions. Research suggests that virtual therapy can offer similar benefits to in-person sessions for conditions like depression and anxiety. If you’re interested in trying the online therapy format, you might consider a platform like BetterHelp. You can get matched with a licensed therapist who you can speak with via phone, video call, and/or online chat about any symptoms of a mental illness that you may be experiencing, or any other mental or emotional challenges you might be facing.