Can Light Cure Seasonal Affective Disorder?

As winter approaches, Canadians are gearing up for the coldest and darkest days of the year. However, many people will face more than just your average winter blues.  

Seasonal affective disorder (SAD) is a mood disorder linked to the changes in seasons. It sets off the same symptoms as major depressive disorder, including a loss of interests, feelings of hopelessness, troubles concentrating, low energy and fatigue. Generally, symptoms begin in the fall and last for the duration of winter. Studies show that 2 to 3% of Canadians will experience seasonal affective disorder in their lifetime, and 15% will experience SAD in a milder form. 

“Seasonal affective disorder refers to the fact that at certain points in the year, you may not be getting adequate sunlight,” says Dr. Praveen Arany, an assistant professor of Oral Biology at The University of Buffalo. 

Dr. Arany specializes in therapeutic uses of lasers and light. Through his research, he’s found human health to be critically dependent upon light. 

“The body’s biological clock uses sunlight as an internal signal to keep your health ideal,” says Dr. Arany.  

To manage symptoms and improve daily function, Dr. Arany recommends using light therapy.

Light therapy, also known as phototherapy, requires sitting or working near a lightbox that projects artificial light to compensate for the lack of natural sunlight exposure. Treatment begins in the fall and continues until there is a sufficient amount of sunlight in the spring. Symptoms may improve within a few days to a few weeks. Sixty to eighty percent of people with SAD find significant relief from light therapy. 

Here’s what a lightbox used for light therapy can look like.

Lightboxes are used to treat a variety of health conditions. However, health issues or not, Dr. Arany believes light therapy can be beneficial to everyone. 

“We are not normally cycling as human beings are supposed to be. We are in all of these artificial places with big screens, and that’s why I think all this research on seasonal affective disorder can make a big impact on our general health, and light is an important part of that,” says Dr. Arany. 

Not all lightboxes are made equally! Here is how to choose a lightbox: 

UV Filter – Light therapy is not to be confused with tanning beds. Avoid lightboxes that use UV light, which can be harmful to your eyes and skin. 

Intensity – Lightboxes should illuminate 10,000 lux at a comfortable sitting distance. Certain light boxes require you to be too close to the screen to attain any benefits. Carefully check the distance suggested before purchasing. 

Spectrum – White light is preferable. Avoid lamps with colour temperatures above 5000 Kelvin. 

Size – Avoid lightboxes that project light from a small area, as they diminish the therapeutic dose of light to the eyes.

Similar to medication, light treatment duration and doses are prescribed differently for everyone. Consult with your doctor before starting light treatment to ensure light therapy is right for you. It is unlikely that light therapy will cure SAD, but it can help manage symptoms. 

“Light should be a part of the spectrum, especially in clinical care, we don’t think it’s going to cure everything, but it’s an important part that is getting more attention,” says Dr. Arany. 

• health
• light therapy
• mood
• sad
• Seasonal Affective Disorder
• Seasonal Depression