Staff Perspective: The Use of Light Therapy for Seasonal Depressive Symptoms

Staff Perspective: The Use of Light Therapy for Seasonal Depressive Symptoms

After returning to the Pacific Northwest (following living in sunny California for several years), I was quickly reminded of the dark, gloomy winters of this latitude; going to work in the dark and coming home in the dark. If you are lucky to have a window or get outside, it is likely overcast with a sputtering of rain and you quickly shuffle from your car to either work or your home dodging puddles along the way. For some individuals, the short days of December, January, and February can lead to the experience of the “winter blues”. For others, this continuous gloom can manifest in meeting the criteria for Seasonal Affective Disorder (SAD), a type of major depression with a seasonal pattern.

The exact cause of these seasonal depressive symptoms is unknown but there are several factors that may be contributory. Researchers have found individuals with SAD have difficulty regulating the neurotransmitter serotonin and an overproduction of melatonin, both of which influence circadian rhythms. This internal 24-hour clock synchronizes our body clock and is set each day by light exposure. During the winter months, with shorter days and reduced light exposure individuals may notice a delayed shift to their rhythm and a reduction in Vitamin D production, contributing to depressive symptoms such as sleepiness and lethargy. Severity of symptoms can vary from mild symptoms known as “winter blues” to more severe manifestations resulting in incapacitating symptoms (Melrose, 2015).

There are several well-researched treatment approaches to address these potential contributors including psychiatric medication, psychotherapy, Vitamin D and light therapy (Melrose, 2015). One thing I have found living here is that you can easily find light boxes or devices that produce artificial sunlight; available for purchase at the local Costco or BedBathandBeyond. During my fellowship in Behavioral Sleep Medicine, we used them in the treatment of Circadian Rhythm Disorders, but I was particularly curious about the efficacy of these devices in mitigating seasonal depressive symptoms.

Known under several names, you may hear the terms phototherapy, light therapy, or bright light therapy. There are multiple types of devices that allow an individual to acquire that missing sunlight, particularly in the morning when we are most sensitive to light. The research base is growing for the use of light therapy for a multitude of behavioral health conditions. Strong research supports its use in those with circadian rhythm misalignment and disorders including those caused by jet lag, helping adjust and entrain our circadian rhythm. There is also research in the use of phototherapy with individuals with SAD, as well as non-seasonal depression, not only as a monotherapy but used in conjunction with psychiatric medications. New research is even looking at the use of bright light therapy with individuals with ADHD, Parkinson’s and Alzheimer’s disease (Campbell, et al., 2017).

The first use of phototherapy as a treatment of Seasonal Affective Disorder was demonstrated by Rosenthal et al. in 1984, when researchers exposed participants to bright white light (2,500 lux – a measurement of light intensity) for three hours twice a day for several weeks. Participants in this seminal work experienced a significant reduction in depressive symptoms. The exact mechanisms of action for bright light therapy is unclear but there are hypotheses that light therapy corrects circadian rhythm delays caused in the winter months and may increase synaptic serotonin.

There are multiple options for phototherapy or light therapy including boxes, visors and even glasses ranging in price. Some insurance companies may even pay/reimburse for a light box for SAD. The recommendations on when and how long to use the light box depend on the diagnosed condition and its intended purpose and should be initiated and monitored under the guidance of a health professional. For seasonal depression, research indicates that symptoms can be relieved with the use of one of these devices first thing in the morning from fall to winter using a device of 10,000 lux with a UV filter for 20-60 minutes with standard treatment. (For comparison, an individual may be exposed to approximately 150 lux indoors, 10,000 lux on a cloudy day, and 50,000 to 100,000 lux on a sunny day.) How much lux an individual is exposed to depends on the angle, position, and distance from the user’s eyes so carefully read the manufacturer’s instructions.

Light therapy does require time and commitment, as you need to use it regularly for at least 20 minutes daily for weeks to months to get the most benefit. There is a risk of adverse side effects, as well as interaction effects with certain photosensitizing medications. Some individuals have reported headaches, eye strain, and nausea, especially when first using the device. The use of phototherapy is cautioned in certain individuals such as those with Bipolar Disorder, as it may trigger hypomania and suicidal ideations. These individuals should work closely with their psychiatrist or a medical practitioner who specializes in using phototherapy as the treatment can be modified (Cambell et al., 2017).

If interested in light therapy…

  1. Talk to a professional. If you are experiencing symptoms of depression speak with your physician and/or a licensed behavioral health provider about your experience to see if you are a good candidate for light therapy. They may be trained in light therapy or can refer you to someone who is. It is recommended you always consult with a healthcare professional due to potential side effects and/or interactions with medications.
  2. Speak with your insurance company. Depending on your diagnosis, some insurance companies may pay for or reimburse you for a light box with a prescription from your physician.
  3. Research light therapy devices. There is a variety of light boxes and other devices out there but you need to do your research. Most suggest a box with 10,000 lux and a UV filter but depending on your condition and your treatment plan, you may need a device with less lux to start with or can get one that has adjustable brightness.
  4. Follow the instructions and guidance of your provider. To get the most benefit, after creating a light therapy treatment plan with your therapist, read the device instructions carefully on how close you need to be to the box to get the full 10,000 lux and how long you need to use it for each day.

For interested providers: If you would like to learn more about the use of light therapy in clinical practice, you can review the resources below. There is also a website from the Center for Environmental Therapeutics (2020) that also offers articles and suggestions on books to learn more about how to incorporate this into your clinical work. The Center for Deployment Psychology also has Sleep subject matter experts available for consultation and guidance at

Light therapy has shown to be an effective treatment for a range of symptoms and disorders, including seasonal depressive symptoms such as the winter blues and Seasonal Affective Disorder. Individuals treated with light therapy have reported significant shifts and entrained circadian rhythms, as well as improving morning alertness. In my own clinical practice I am excited to see how light therapy can be used with other symptoms/ disorders. It does take time and commitment for benefits but can be an alternative or adjunctive treatment to medication. I must admit, I have a new lightbox sitting on my bathroom counter to help combat these long winter nights.

Staff Perspective: Seasonal Affective Disorder - Is There an App for That?

The opinions in CDP Staff Perspective blogs are solely those of the author and do not necessarily reflect the opinion of the Uniformed Services University of the Health Science or the Department of Defense.

Nichole Mogharreban, Psy.D., is a Military Internship Behavioral Health Psychologist with the Center for Deployment Psychology (CDP) at the Uniformed Services University of the Health Sciences in Bethesda, Maryland. Dr. Mogharrenan is located at the Madigan Army Medical Center Clinical Psychology Training Programs at Joint Base Lewis-McChord, Washington.


Campbell, P., Miller, A., & Woesner, M. (2017). Bright light therapy: Seasonal affective disorder and beyond. Einstein Journal of Biology and Medicine, 32, 13-25.

Center for Environmental Therapeutics (2020). Light Therapy.

Melrose, S. (2015). Seasonal affective disorder: An overview of assessment and treatment approaches. Depression Research and Treatment, 2015, 1-6.

Rosenthal, N., Sack, D., Gillin, J., Lewy, A., Goodwright, F., Davenport, Y., Newsome, D., & Wehr, T. (1984). Seasonal affective disorder: A description of the syndrome and preliminary findings with light therapy. Archives of General Psychiatry, 41(1), 72-80.