Seasonal Affective Disorder (SAD) and Light Therapy

Temperatures are dropping, daylight hours are decreasing, and the holiday season is upon us. The Michigan winter is here!!  For many people, shorter and darker days mean an increase in depression symptoms.  For some, these symptoms result in Seasonal Affective Disorder, or SAD.   

What is Seasonal Affective Disorder?

Seasonal Affective Disorder (SAD) is a form of depression that occurs at the same time each year, usually beginning in the late fall to early winter months and ending in the spring.  Mild forms of SAD are commonly referred to as “winter blues,” but some people have a more severe form which requires treatment. 

What causes SAD?

No one is exactly sure what causes SAD, but it may be related to the fewer hours of daylight during the autumn and winter.  The reduced amount of sunlight can affect levels of chemicals and hormones in the brain such as serotonin and melatonin.  Serotonin plays a role in lifting mood, and melatonin affects sleep and mood patterns.  People with SAD are thought to respond to a decrease in light by producing too little or too much of these chemicals. 

What are the symptoms?

What is the treatment for SAD?

People can take a number of steps to lessen the effects of SAD. 

What is light therapy?

Research has shown that exposure to bright artificial light can improve symptoms in two out of three cases of SAD.  A 10,000-lux light box administers light therapy (“Lux” is a unit that measures illumination).  This light is at least 10 times stronger than normal light bulbs, is very similar to natural daylight, and won’t harm the eyes. 

How is light therapy used?

How soon does light therapy work?

Most people notice improvement in 2 to 4 days.  In some cases, symptoms may not improve for several weeks.  If symptoms get worse or do not improve after 4 to 6 weeks, consider additional treatment options.

Are there any side effects or risks with light therapy?

Side effects are uncommon but may include:

Criteria for light boxes

Depending on the product you buy, the cost of light boxes can range from $150 to $400.  Keep in mind some insurance companies will help with the cost and you can also use your Health Flexible Spending Account towards this purchase.

Never use homemade light units, such as tanning lights or beds, for light therapy.  The light given off by these units is high in UV rays and can harm your skin and eyes.

Consider these factors when considering buying a light box:

This information has been brought to you by the M-DOCC program, a unique, telephone-based collaborative care program for depression management that complements care provided by a patient’s physician. Care managers are experienced mental health social workers who work on behalf of the referring clinician and provide direct feedback to the patient’s treating team. Find out more.



Are you doing all you can to manage your depression? Check in with yourself and find out.

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