I was assked to write an “Ask the Doctor” newspaper column in my community in response to a reader question about whether there really is such a thing as “Winter Blues.” Here is my first draft of a response. What do you think?

For millennia, humans have reacted with discomfort to the waning of the light and the shortening of the days as we slide into winter each year. It is no accident that many, if not most, cultures have a celebration of rebirth and affirmation of hope around the winter solstice. When we lived closer to nature, there was arguably nothing wrong with ramping down, reducing activity and conserving energy and resources to get through the cold dark nights, to which one writer has referred as “winterizing the soul”. Even if not an annual event for most people, the “winter blues” are common – and distressing. Going to ground, slowing down the pace and enjoying quietude can cause tensions in a modern non-agrarian society that expects activity, outwardness and productivity with no regard to seasonal rhythms. Beyond the biological factors, of course, the wintertime may be hard for other, strictly emotional reasons. Many people have a difficult time around the holidays, which are supposed to be so warm and congenial for us all but often are anything but.

Beyond just feeling down, however, an estimated 15 million Americans experience a full-blown medical syndrome called seasonal affective disorder (SAD) during the colder, shorter days of winter. Most SAD sufferers experience normal mental health through much of the year but experience wintertime symptoms including depression, social withdrawal, excessive sleeping, overeating and weight gain, difficulty with motivation and energy and problems taking care of themselves and those for whom they are responsible . SAD may be severe enough to require psychiatric hospitalization. Women tend to report the condition far more than men, reflecting either hormonal issues or men’s greater reluctance to admit to feeling down.

Seasonal mood variations are believed to be biologically related to decreased light exposure. They vary with the latitude, with higher incidence in the Scandinavian countries and Arctic regions, and also with the typical degree of cloud cover in an area’s climate. Many sufferers can extinguish their symptoms with lifestyle measures such as increased exercise and outdoor activity, especially on sunny days. Light therapy, with specially designed lights many times brighter than normal indoor lighting, is perhaps the most effective specific treatment. Many patients, however, stop the treatment because of the inconvenience, since they must sit close to the light with their eyes open for 30-60 minutes at a consistent time of day each day. Benefits are often apparent only after several weeks. Many antidepressants have also been shown to be beneficial in serious SAD symptoms.

The vulnerability to SAD may be at least partly genetic, and it may be genetically related to manic depressive illness (bipolar disorder), as it tends to cluster in the same families. In fact, some psychiatrists consider SAD (as well as postpartum and perimenstrual mood disorders in women) to be a form of bipolar disorder, which may lead to treatment with lithium or other mood stabilizers.