How to Harness Light to Defeat the Winter Blues

The winter blues can sap your energy, disrupt your sleep, and destroy your concentration, but there's a simple key to defeating it—light. Here's how it works!

Jade Wu, PhD
5-minute read
Episode #272
The Quick And Dirty
  • Our moods are deeply affected by the hours of available daylight, which diminish in wintertime, especially for those who live far from the equator
  • Three percent of people experience a more severe mood downturn called Seasonal Affective Disorder (SAD)
  • Artificial bright light therapy in the morning can boost mood and alleviate SAD symptoms
  • Bright light exposure at the wrong times can be counter-productive

Winter can be a beautiful time full of holiday cheer, gorgeous snowscapes, and fun activities like sledding and skiing. But even with all this fun, some people can't help but experience the winter blues. Their mood takes a dip in the fall and winter even when life is otherwise going well.

Is it winter blues or Seasonal Affective Disorder (SAD)?

For about 3 percent of people, this mood downturn is so severe that they have something called Seasonal Affective Disorder (SAD). They not only feel blue but they also experience:

  • Loss of interest in things they usually like
  • Unusual tiredness or sluggishness
  • Trouble sleeping
  • A tendency to overeat and gain weight
  • Difficulty concentrating and thinking clearly
  • Feelings of hopelessness, or sometimes even having suicidal thoughts

Why does this happen? Is there a way to beat the seasonal blues?

Light may be the key to beating the winter blues

The secret may lie in light. That’s right, the free resource that comes from our sun. Plants rely on soaking up light to make food and grow, but it turns out that we animals need light too. Our biology is so wrapped up with light that our metabolism, mood, and thinking are all affected.

Here are some things to know about why light is important for mental health and how to harness it for better health and happiness, especially in the winter months:

Our mood is intimately tied to light

The winter blues and SAD don’t just happen to people because they don’t like winter. There is actually a biological reason for winter depression. Here's a clue: The people most susceptible to winter-induced depression are those living far from the equator. Living farther away from the equator means you get fewer daylight hours in the wintertime.

Light is the single most powerful factor in tuning your body clock.

Because there's less daylight during fall and winter, the body’s circadian rhythm gets disrupted. Light is the single most powerful factor in tuning this body clock, and with less and less of it as we move from fall to winter, the body’s natural rhythms can become less robust. That's bad for your mood, metabolism, cognitive functioning, and many other body systems that play a role in depression. It’s also possible that less sunlight leads to a drop in serotonin, a brain chemical that's important for regulating mood.

Artificial light can boost mood and keep winter blues at bay

The good news is that by artificially adding light to our lives, we can combat the winter blues! Numerous studies have shown that something as simple as using a lightbox can decrease symptoms of SAD. Ideally, you’ll want a full spectrum light source, such as a lightbox designed for this treatment. But even a very bright bulb from the hardware store can help.

Bright light therapy improves your mood by regulating your circadian rhythms and increasing serotonin.

Standard treatment involves using the light for about 30 minutes each morning if it has a brightness level of 10,000 lux, or for about 1-2 hours if it has a brightness level of 2500 lux. For comparison, 10,000 lux is on the low end of ambient daylight, whereas an overcast day is about 1000 lux.

To avoid hurting your eyes, don’t stare directly into the light. Instead, have it offset about 30 degrees from your gaze and about two feet away. You can have your breakfast, check email, or enjoy a morning podcast while you have your lightbox on.

Bright light therapy improves your mood by regulating your circadian rhythms and increasing serotonin. What’s especially great about this treatment is that it can be easily combined with medications or other treatments without interfering or introducing side effects.

There are studies showing that bright light therapy can be combined with taking an antidepressant for an extra boost even in people with year-round depression.

Bright light therapy helps not only with winter blues but with sleep and daytime fatigue

When it comes to sleep, bright light therapy may have an even more direct effect. Often, those with depression (especially seasonal depression) also have later chronotypes, meaning that they are biologically wired to want to sleep and wake later than the average person. This means they’re dealing with a double whammy during winter—they have both a depressed mood and a harder time getting up in the morning.

Bright light therapy first thing in the morning can help to shift night owls’ biological clocks earlier, improving how they sleep at night and how alert and refreshed they feel in the morning.

Luckily, doing bright light therapy first thing in the morning can help to shift night owls’ biological clocks earlier, improving how they sleep at night and how alert and refreshed they feel in the morning.

Bright light doesn’t just help night owls to feel good during the day and sleep well at night. For those with chronic illnesses like Parkinson’s disease and Alzheimer’s dementia, and for those recovering from illnesses like cancer, bright light therapy helps to reduce fatigue and sleepiness during the day. For these patients, light therapy might be particularly welcome news because it's a way to treat symptoms without adding more drugs to their regimen.

Too much of a good thing (at the wrong time) can be counter-productive

If light is so magical, we should all get lots of exposure any time we can, right?

Actually, timing is very important with light therapy.

Remember how light is the strongest tuner for our body clocks? It works by telling our master clock, the suprachiasmatic nucleus, what time it is in the 24-hour cycle. That means light at the wrong times can have exactly the wrong effect. For example, using screens in the evening can disrupt sleep by making a person more alert at bedtime, which means they could have a harder time falling asleep or getting into a deep sleep.

Too much brightness in the evening might contribute to depression symptoms.

It’s not just sleep that’s affected by light at night. Too much brightness in the evening might contribute to depression symptoms, too. One study found elderly people who were depressed were more likely to have brighter environments at night. This was true even after the scientists accounted for sleep, physical activity, and other health factors that might affect depression.

Don’t worry, though—this doesn’t mean you have to put away all of your screens after sunset. It turns out that not all wavelengths of light affect our brains the same way. Shorter wavelengths like blue light stimulate the brain’s master circadian clock, while longer wavelengths like red and orange lights do not. That’s why our cavemen ancestors’ body clocks were not disrupted by their evening campfires.

To mimic the campfire effect, you can turn your phone or tablet screen to night mode, which is dimmer and more orange. You can also wear blue-light-blocking glasses, which are spacey-looking glasses that filter out the shorter wavelengths that affect your circadian clock. Just don’t wear them during the day, because that’s when we do want bright blue lights to come through.

So, brighten up this winter and use the power of light to live healthier and happier!

All content here is for informational purposes only. This content does not replace the professional judgment of your own mental health provider. Please consult a licensed mental health professional for all individual questions and issues.

About the Author

Jade Wu, PhD Savvy Psychologist

Dr. Jade Wu was the host of the Savvy Psychologist podcast between 2019 and 2021. She is a licensed clinical psychologist. She received her Ph.D. from Boston University and completed a clinical residency and fellowship at Duke University School of Medicine.