SADness: Seasonal Affective Disorder Part I—What is SAD?

I’ve been meaning do write about Seasonal Affective Disorder (SAD)—what it is and my experience with it. Since we are approaching the Winter Solstice–the shortest day of the year–it seemed the perfect time to start a series of posts about SAD.

SAD was first described by Dr. Norman E. Rosenthal and colleagues in a 1984 article in Archives of General Psychiatry [1]. Simply stated, SAD is extreme winter blues. This is different from the cabin fever people often experience after being shut inside for too long during the winter. People suffering from SAD experience actual clinical major depression during the winter months, then remission from depression (sometimes even hypomania) during the summer. The severity can vary from person to person and from winter to winter. Some people are mildly affected while others experience significant impairment. While anyone can suffer from SAD, women in their 20s to 40s are the most susceptible.

The symptoms of SAD are very similar to the symptoms of standard clinical depression—depressed mood, sleep difficulties (usually increased daytime sleepiness and prolonged nighttime sleep for people with SAD), changes in eating patterns (generally overeating and carbohydrate craving for SAD sufferers), and low energy—but, significantly, these symptoms of depression routinely show up in the winter and abate in the summer. People with SAD may also have difficulty thinking clearly and concentrating during the winter months. In the summer, people with SAD often feel happier, more energized, sleep better and can think more clearly.

Classically, SAD is triggered by the decreasing amounts of sunlight experienced as the seasons progress from summer to winter. As the days get shorter, the symptoms worsen. However, SAD can also show up when a person changes latitudes—going from a lower latitude to a higher latitude can cause the onset of SAD while going from a higher latitude to a lower latitude can alleviate the symptoms of SAD. In his book, Winter Blues [2], Dr Rosenthal describes a case in which a person developed SAD after he quit smoking and therefore no longer went outside in the afternoons for a smoke break!

The onset of SAD symptoms occurs at different times for different people. Some people may feel fine until November, others start to become depressed in August. Remission can also occur at different times in the spring. Interestingly, the worst months for SAD are usually January and February (in the Northern latitudes), after the days have started getting longer. This is because these are often the months with highest frequency of cloudy days (and so, the least amount of sunlight). Therefore, although the Solstice should mark the beginning of the road to happiness for SAD sufferers, in reality the worst may be yet to come.

Coming up: Light Therapy for SAD


1. Rosenthal NE, Sack DA, Gillin JC, Lewy AJ, Goodwin FK, Davenport Y, Mueller PS, Newsome DA, Wehr TA. Seasonal affective disorder. A description of the syndrome and preliminary findings with light therapy. Arch Gen Psychiatry. 1984 Jan;41(1):72-80.

2. Rosenthal, NE. Winter Blues. New York: Guilford Press, 1993; second edition 1998


5 thoughts on “SADness: Seasonal Affective Disorder Part I—What is SAD?

  1. I find the ‘reveal’ lights very helpful for this. They are kinda purple/bluish, and they seem like summer sunlight.

    I’ve not been legit diagnosed for this, but I am almost certain that I suffer. The weird part is that summer is not my favorite season, fall is.

  2. Thanks for the article! I need to research my condition more. I hadn’t been actually labelled with SAD until a few years ago. I did notice a few things for years before that: exercise journals showed that I’d stop around October 31 and resume in early March after I’d packed on 30 pounds to the pound. I have ended friendships in January. I dropped out of college in January. Most years I drop the 30 pounds by June. I have been using the lightbox for about a week for 30 minutes in the morning and no noticeable difference in fatigue. I am amazed how much I’ve slept over the past few weeks when I get a chance. This became noticeable starting the end of October. On the converse, I have a hard time getting to sleep at night! This year, I was prescribed Lunesta which I have been taking for about 30 days. My SAD starts on August 17th and ends on February 17th each year. My symptoms are a moderate level of grouchiness (not constant) and a pervasive drugged-like fatigue during the day with numerous 1 1/2 naps. Just had a physical last June and otherwise am as strong as an ox.

  3. It was interesting to go back and read your posts with the label mental illness. I suffer from mental illness too, but for me it’s depression (and I’m a recovered bulimic). It’s interesting to read about this because I like to hear about how other people deal with their depression symptoms or their own mental illnesses. It’s also striking to me how I don’t think I have SAD at all – I really couldn’t care less about whether I even see much daylight or sleep during the day and wake at night instead, or whether I’m outside, and I’m much more irritable in the summers because of all discomforts of summer in the city.

  4. It may be that it is not lack of sunlight but lack of something related to sunlight — vitamin D.

    A randomly controlled study comparing alleviation of seasonal depression by wither light therapy or vitamin D supplementation clealy showed vitamin D to be superior.

    I take 5,000 IU a days October through April and 2000 IU / day May-September.


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    Do you have any suggestions on how to get listed in Yahoo News?

    I’ve been trying for a while but I never seem to get there! Appreciate it

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