If you find that your mood is dropping along with the temperatures, you’re hardly alone. In fact, experts believe that up to one in five Americans will experience the so-called winter blues each year.

In most cases, winter blues amount to some mood swings and minor social withdrawal, which correct themselves as the Earth rotates back towards the sun.

But for millions of others, their depressive symptoms are severe and long-lasting, affecting how they eat, sleep, think, and relate to others. 

One of those people was Diana Lillo, 55. Though her symptoms changed a bit from year to year, every winter she found herself with “depression for no apparent reason—a generalized feeling of ‘doom and gloom’ even when nothing in particular was wrong.”

Lillo knew she needed help when it began to affect her marriage. A psychiatrist ultimately diagnosed her with SAD.

“Seasonal affective disorder, or SAD, is clinical depression that follows a seasonal pattern,” says Kelly Rohan, PhD, Professor of Psychological Science and Director of Clinical Training at University of Vermont. Experts aren’t exactly sure why it occurs, but they agree that a lack of sun plays a major role. 

One theory is it screws up your biological clock, leading to depressive symptoms. Or, it’s possible that limited sunlight messes with brain chemicals, like serotonin and melatonin, that affect sleep and mood.

As such, Americans who live far from the Equator—say, in North Dakota—are more prone to SAD that those who lives in sunnier climes. Women in general tend to suffer more than men, and anyone with a family history of depression is definitely at higher risk. 

Left untreated, SAD can be life-altering, and even incapacitating.

Older folks, too, may mistake the signs of SAD as normal aging. And, they could have existing medical issues that mimic some of the same symptoms.

Left untreated, SAD can be life-altering, and even incapacitating—so it’s important to recognize the signs. Here’s what you need to know.

SAD vs. the blues

If you have typical winter blues your symptoms will likely be pretty mild. “Perhaps you feel a little less energetic than you do in the summertime, and have some food cravings that are unusual, like wanting to eat more carbohydrate-rich foods, or you sleep a little more, but not substantially more,” says Rohan. These feelings will often go away on their own, maybe after just a few days.

SAD, on the other hand, usually causes more serious oversleeping, appetite changes, weight gain, lethargy, and social withdrawal. You may also experience intense sadness, feelings of hopelessness or worthlessness, irritability, problems concentrating, and even thoughts of suicide. 

Moreover, if you have SAD, those symptoms will hang around “for at least two weeks, if not longer, most of the day, nearly every day,” says Rohan. They’ll affect your daily function and ability to do things, and cause a lot of distress, she adds. 

That’s what happened to Lillo, who found herself “going deeper and deeper into depression until suicidal thoughts appeared every winter.”

The “every winter” part is key: If your depressive symptoms have appeared for at least two years in a row, and haven’t materialized during other seasons, there’s a good chance that SAD is the reason.

How to ease the pain of dark days

If you think you might have SAD, it’s critical that you discuss it with your doctor. He or she may recommend therapy or antidepressants, in addition to some strategies you can try at home:

Maximize your daylight: Rohan suggests starting with a morning walk. “It does two things,” she says. “It gets the light that is available to your retina, which can help reset a biological clock. And it gets you moving in terms of physical activity.” Exercise can boost your mood and ease your mind, and some studies show it helps relieve SAD, specifically.  

Also, open your shades, park yourself by windows, and head outdoors whenever possible, weather permitting. And it can’t hurt to schedule a warm-climate vacation during the winter months, suggests Ani Kalayjian, PhD, Adjunct Professor of Psychology at Columbia University’s Teacher’s College and author of Forget Me Not: 7 Steps for Healing Our Body, Mind, Spirit, and Mother Earth.

“Withdrawing from routines sets you up for what I call going into hibernation mode, which really breeds depression.”
Kelly Rohan, PhD, Professor of Psychological Science and Director of Clinical Training at University of Vermont

Avoid isolation: “Go meet up with that group you belong to or go to the gym or go see that movie, see friends for coffee,” says Rohan. “Withdrawing from those routines sets you up for what I call going into hibernation mode, which really breeds depression.”

Ask about light therapy: Your doctor can prescribe this treatment, where you’ll spend time each morning sitting near a special box that emits very bright light. This emulates the effect of the sun, and has been shown to work for up to 70% of SAD patients.  However, not all insurance plans will cover the cost of the boxes.

Finally, once you’ve been diagnosed with SAD, make sure you’re prepped for the future. This can involve anticipating “down” times, planning activities ahead, and watching out for worsening symptoms.

It may also mean beginning treatments before symptoms kick in. Because ultimately, when it comes to SAD, the best defense is a good offense.