What is SAD?

SAD is a form of clinical depression that affects roughly 10% of Americans. It is much more serious than temporary feelings of sadness that may come with colder, darker months, according to Kelly Rohan, a professor of psychological science and a clinical psychologist at the University of Vermont.

"One big, common misconception about SAD is that it's just the 'winter blues,'" Rohan said.

The difference between having "just winter blues" and SAD is "the pervasiveness of feeling sad or depressed pretty much all the time, having loss of interest in things that used to give you pleasure," ter according to Petros Levounis, president of the American Psychiatric Association.

According to the National Institute of Mental Health, you may have SAD if you experience certain symptoms that begin and end during specific months and occur for at least two consecutive years. These symptoms can include daily feelings of depression, loss of interest in activities you enjoy, appetite or weight changes, sluggishness and low energy, difficulty falling asleep or oversleeping during the day, and thoughts of death or suicide.

SAD is more common in women than men and is especially more common among those living in the northern regions of the United States, like Alaska and New England, than those living in the south.

"People may not appreciate how severely someone who has SAD is affected," said Paul Desan, a psychiatrist at Yale School of Medicine. For some, "their life just shuts down for half the year."

According to Rohan, shorter, darker days trigger depressive symptoms in patients with winter SAD, but experts are unsure why this happens.

One theory predicts it has to do with the body's melatonin production. At night, the body typically produces melatonin to help promote sleep. Levels of melatonin then taper off as the sun rises, which helps people wake up.

But if you have winter SAD, melatonin peaks later and stays longer in the morning, making it more difficult to wake up and making you feel fatigued and groggy. Since you don't reach peak wakefulness until later in the day, it becomes more difficult to sleep once evening comes, which can begin a cycle of insomnia, poor sleep, and fatigue, which can exacerbate depressive symptoms.

Most people who have SAD are usually susceptible to feeling down, according to Kathryn Roecklein, an associate professor of psychology at the University of Pittsburgh. But in the winter, when light levels fall below a certain threshold, things can get off balance.

There's also evidence that negative anticipation of shorter days in the winter, such as thinking "I just don't function well in the winter" or "I'm going to start feeling poorly soon," can combine with other biological effects to create a self-fulfilling prophecy, Roechklein said.

Symptoms of SAD can linger for a while, up to five months for some, according to Lily Yan, a professor of psychology and neuroscience at Michigan State University.

Generally, most people with winter SAD will start noticing symptoms between October and November, Rohan said. But if you live in an area of the United States where people are more susceptible to SAD, you could notice those symptoms earlier in the fall. In addition, stressful life events can also jump start depressive episodes earlier than normal.

How to treat SAD

There are multiple evidence-backed ways to treat SAD. One of these is bright light therapy, which involves sitting in front of a light therapy box that mimics outdoor light for around 30 minutes every day when you wake up. Doing so should stimulate your body to produce the correct hormones to increase your alertness and wakefulness, according to Desan.

"Bright light treatment first thing in the morning dramatically improves the vast majority of people with seasonal affective disorder," Desan said.

Rohan noted that you should make sure you're using it correctly. If you don't use it early enough, it might not work, and if you use it too late in the day, it could make insomnia worse. Most experts recommend using light therapy lamps before 8 a.m.

When searching for a light therapy lamp, Desan said you'll want one that advertises 10,000 lux brightness, which is the equivalent to a bright summer morning. He added that a good light therapy lamp should be "full spectrum" as well, meaning it closely mimics natural morning sunlight.

Cognitive behavioral therapy (CBT) can also help treat SAD, Rohan said. If you say something like "I hate winter" in a therapy session, a therapist may try to shift those negative thoughts. "Even if we could take it down a notch to, 'I prefer summer to winter,'" Rohan said, that can help significantly.

Since CBT for SAD means retraining negative associations with darker months, it's the only therapy for the condition that could have long-term benefits after doing it just once, Roecklein said. "It works in the winter when that person comes in for a treatment, but then it also protects them from depression the next winter and the winter after that," she said.

Some antidepressants can also help treat SAD, including selective serotonin reuptake inhibitors like Prozac, Celexa, and Zoloft. Wellbutrin, a different type of antidepressant, is currently the only drug approved by FDA for treating seasonal major depressive episodes.

In addition, going outside for a walk can help improve your mood, Yan said, as the quality of light outside will be better than what you can get at home. Research has found that taking a walk among trees and nature can be good for your mental health, as we've been trained to associate nature with calmness, Levounis said.

Rohan added that replacing your favorite activities in the summer with similar wintertime activities can "bring a sense of enjoyment into life." For example, if you love sitting by a lake in the summer, you could do some version of that, perhaps putting on snowshoes and walking around or skating or sledding.

"It may take some creativity and problem-solving," Rohan said, but it could help you find a way to engage positively with the season. (Seo, New York Times, 11/3; Mallenbaum, Axios, 11/6)

According to a study published in Nature Mental Health, people who had a broad range of healthy lifestyle factors were able to reduce their risk of depression by more than half — findings that health experts say underscore the importance of habits and behaviors in good mental health.