Seasonal affective disorder (SAD) is not a formal diagnosis but a pattern of depression commonly tied to the shorter days of fall and winter.
The dread of approaching winter can begin to creep in as early as the peak of summer. The slow but inexorable decrease in the amount of daylight reminds one that the season is changing. Seasonal affective disorder (SAD) is not a diagnosis; it is a description of a particular pattern of depression.
What Is Known About Seasonal Affective Disorder (SAD)?
SAD refers to depressions that regularly occur in a seasonal manner, typically starting with the shortening of the days in the late summer or fall. In order to be called SAD, the pattern of depression must occur in at least two seasons in a row.
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Some people show a seasonal pattern for a few years, and then it goes away. Others have depression that suddenly changes by showing a seasonal pattern. A person who becomes depressed in the winter may assume that the reason for the depression is the winter, when in fact it might simply be an underlying depression that has a rhythm that is unrelated to the season.
The simple fact remains that patients tell me all the time that a trip to the South is essential to boost their mood during the winter months. Others feel that using a light box is critical to their mood management.
What Are Some Effective Treatments for SAD?
There are many controversies surrounding SAD and its treatment. Studies in the mid-1980s on the efficacy of light therapy spawned a tremendous amount of enthusiasm; more recent studies, however, have not reported resounding success.
If you recognize a seasonal pattern to your mood swings, it’s fine to try light therapy. Typically, people tell me they do feel improvements but that it does not carry the day. In less than 10 percent of people, there is a strong response suggesting that light therapy did indeed do the trick.
If light therapy is going to help, typically you will notice a difference within a couple of weeks, and in combination with other treatments, a light box can make the winning difference.
The potential side effects are generally minimal (eye irritation); however, sleep difficulties, elevated energy, and even mania can occur. It can be tempting to overuse the light box as the increased energy is welcomed in the gloom of winter, so it is wise to let a close confidant know you are using light treatment, inform them of the risks, and ask them to keep an eye on you.
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The primary management of mood issues during the darker seasons should be guided by your healthcare team. By all means, ask about using a light box, but also be sure to discuss sleep management. Consider whether a seasonal adjustment to your treatment plan might help — this could involve changing your medication dose or adding another medication during the winter.
You might also talk with your clinician about trying social rhythm therapy. This approach involves setting regular times for waking, social engagement, evening meals, and bedtime to help maintain a steady daily routine. Social rhythm therapy has been shown to be very helpful in reducing mood swings.
Why do Some People Have SAD?
The exact reasons and mechanics behind seasonal affective disorder remain unclear. One theory is that it may reflect nature’s way of pulling back on the reins of your activity levels. When you’re physically ill, for example, emotional fatigue and a systemic low-energy state (much like clinical depression) encourage rest and help the body recover more quickly. Depression in the absence of physical illness may be a misfiring of that natural response, as happens with many diseases.
Many animals hibernate throughout the winter. SAD may have mechanisms that are similar to the hibernation drive: winter slows down the internal processes of mood and energy. In the spring, one perks up and is ready to go!
UPDATED: Originally printed as “Ask the Doctor: Winter Seasonal Affective Disorder,” Fall 2017