The Benefits Of Light Therapy For Seasonal Affective Disorder (SAD)

Medically reviewed by Karen Foster, LPC
Updated February 29, 2024by BetterHelp Editorial Team

As the seasons change, the clocks shift, and the temperatures drop, it can take a lot to get out the door, especially when it isn't light outside. But if you notice a dramatic shift in your mood and energy levels at the turn of the seasons, you’re not alone. In fact, you may be one of thousands of people who experience seasonal affective disorder (SAD), a mood disorder that typically affects people during the darker months of late fall or early winter. 

Fortunately, if you’re looking for solutions to the seasonal slump, there are several treatments available to help brighten your days and elevate your mood. Below, we’re going to discuss seasonal affective disorder, what causes this form of seasonal depression, and how you can address it by starting light therapy and other solutions.

Can light therapy improve seasonal affective disorder?

Seasonal affective disorder (SAD)

Seasonal affective disorder (SAD), also called seasonal mood disorder, is a predictable occurrence of major depression episodes, manic episodes, or both at particular times of year. Seasonal affective disorder is a type of depressive disorder, a category of mood disorders characterized by low mood, fatigue, lack of motivation, and loss of interest.

According to the American Psychological Association (APA), people with SAD typically experience major depressive episodes during the fall or winter months when light is limited. 

In everyday conversations, you may hear friends or family describe SAD as the "winter blues," “seasonal depression,” or “winter depression.” However, some people experience a rare form of SAD called “summer depression,” beginning in late spring or early summer and ending in the fall. Consequently, SAD is the most widely used and accepted term to encompass a range of individual experiences. 

What causes SAD?

While scientists do not have a full understanding of what causes SAD, research indicates a few factors that may influence its development. Since many people with SAD experience its symptoms in the fall and winter, most scientists and healthcare professionals believe that shorter days – and, in turn, less natural light exposure – negatively affect people with SAD. Studies indicate that sunlight controls the molecules that maintain healthy levels of serotonin. This neurotransmitter affects emotional processing, mood, appetite, sexual desire, the circadian rhythm, sleep quality, and even pain processing. In people with SAD, studies suggest that their brains already have reduced serotonin activity; during the fall and winter when light is limited, their serotonin levels are even lower, resulting in depressive symptoms.

What are the symptoms of seasonal affective disorder?


If you suspect you or a loved one has SAD, you may experience some or all of the following  symptoms:

  • Increased sleep
  • Feeling hopeless, guilty, anxious, or irritable
  • Poor concentration
  • Reduced libido
  • Increased appetite and weight gain
  • Withdrawal from family and friends
  • Lack of pleasure in activities you normally enjoy 

Treatments for SAD

SAD is a challenging condition, but it’s also highly treatable. Scientists have completed a significant amount of research to better understand and support people with this condition. Below are some common treatment options endorsed by doctors, researchers, and counselors. 

Bright light treatment with a light box

One popular form of treatment for seasonal affective disorder is light therapy. Delivered through regular use of a bright light box, research shows that warm light treatment can help reduce symptoms of SAD. Researchers have developed special light treatment lamps that mimic natural sunlight, and may even help your body increase its production of vitamin D. 

Light intensity

As far as light intensity goes, premiere best lamps for light treatment are about 20 times brighter than typical indoor lights and filter out potentially damaging UV light, producing as little UV light as possible. Alternatively, if getting a light box doesn’t seem feasible, people can get similar effects in 30 minutes of natural sunlight – even if wearing sunglasses. 

Can light therapy improve seasonal affective disorder?

What to look for in a light therapy lamp

In addition to any personal health concerns or light sensitivity, it’s best to get personalized recommendations from your counselor or doctor before purchasing your first light box for seasonal affective disorder. Generally, it’s wise to avoid blue light or LED lamps due to any potential harm blue lights pose to your body’s clock and heat from LEDs. 

Important factors to consider:

  • Brightness levels and color temperatures: Look for lamps that project light at 10,000 lux, which is a measurement of how much light the lamp delivers. 
  • Plastic filter: Most quality light therapy lamps include a plastic filter that removes most, if not all, ultraviolet waves, which can cause eye damage.
  • Design: There are many different styles and designs. Some include an adjustable arm and other features that make them easy to assemble as a desk light, on a bedside table, or in a favorite reading spot. 

If you have a history of clinical depression or bipolar disorder, discuss light therapy with your doctor before starting light treatment. According to Dr. Michael Terman, director of the Center for Light Treatment and Biological Rhythms at Columbia Presbyterian Medical Center, people with a history of bipolar disorder or depression may experience an exaggerated response to light therapy, like deepened depression or hypomania

Other treatments for SAD besides light therapy


Depending on severity of your symptoms, your doctor might recommend using of antidepressant medications, antianxiety drugs, supplements, and other medications to improve your symptoms. A counselor cannot prescribe any of these medications, so consult with your doctor or psychiatrist first.

Self-care strategies

Before the expected onset of SAD symptoms, it may also be helpful to solidify and give a self-care plan with friends and family. Your list of self-care activities may include light exercise, cooking a meal with friends or a partner, or making art. By giving this list to loved ones, you can ask loved ones to check in regularly and discuss your progress and needs. 


Even after symptoms of SAD subside, many people find that talk therapy becomes a foundational part of mental health. Talk therapy is especially helpful for the symptoms of SAD. 

Based on results of a 2015 randomized controlled trial published in the American Journal of Psychiatry, cognitive behavioral therapy (CBT) can be an effective treatment for many people with SAD. After 12 sessions of CBT, depressive symptoms of people with SAD improved significantly, and the treatment was comparably effective to light therapy for depression. In general, CBT helps people change negative thought patterns and behaviors and is a promising treatment for a range of mental health conditions. Studies also indicate that CBT can be just as effective when delivered online. 

Online counseling

If you’re experiencing SAD but lack time, energy, or resources for face-to-face counseling, you can engage in CBT and other forms of therapy with an online counselor. Using an online platform like BetterHelp, you can work with a licensed, experienced counselor who has a master’s or doctorate degree in their field. Sessions can be held via phone, video, text, or email. Many counselors have years of experience supporting people with SAD and offer specialized knowledge and coping strategies to improve your quality of life. 


If seasonal affective disorder (SAD) seems to overtake your life during certain months, there are ways to reclaim that time and regain your sense of self, even on the coldest, shortest days. With solid options like light-therapy lamps, your doctor’s guidance, and a green light and support from a counselor, you can emerge from SAD with self–awareness and coping strategies for a healthy, overall happy life – all year-round!

Explore mental health and healing in therapy
The information on this page is not intended to be a substitution for diagnosis, treatment, or informed professional advice. You should not take any action or avoid taking any action without consulting with a qualified mental health professional. For more information, please read our terms of use.
Get the support you need from one of our therapistsGet started