Cold chills, snow and ice and shorter days are getting a lot of people into the holiday spirit, as the change in weather signifies that the winter holidays are on their way. Unfortunately, for an extraordinary number of people, this change in weather can instead bring on the “winter blues.”

It’s hard to ignore the sluggish, cranky or sad feelings you might get when the world outside is a mix of gray and white, and the sky is seemingly nowhere to be found. But why, exactly, does winter weather affect us in this way? And are there ways to combat it and lift your spirits?

Feeling sad because of SAD

One of the most common causes of winter-related mood problems is Seasonal Affective Disorder (SAD), also known as seasonal depression. SAD is not merely an occasional feeling of sadness in winter—it’s a legitimate form of depression that occurs with the changes of the seasons.

SAD is more common in the fall and winter months in areas of the world that have limited access to sunlight—typically, these places are far from the equator.

The disorder can bring about a number of symptoms, many of which are similar to those of major depression, including:

• Irritability
• Feelings of depression or anxiety
• Lethargy
• Difficulty sleeping
• Excessive sleepiness
• Overeating
• Fatigue
• Withdrawing from social situations or favorite hobbies/activities
• Difficulty concentrating

Experts aren’t completely certain why SAD is so common in winter, but it may have to do with a combination of things related to sunlight. First, not having access to as much sunlight can disrupt your circadian rhythms—internal body clocks regulated by sunlight and darkness. This kind of disruption can affect the amount and quality of sleep you get each night, which is necessary for reducing stress and improving your mood. More darkness can also cause higher levels of melatonin—a hormone that makes you feel sluggish or sleepy.

Second, winter weather may cause problems in regulating your serotonin levels—a neurotransmitter known for combatting stress and depression and boosting your mood.

Third, you may get less vitamin D during winter. Vitamin D is created in the cells when you’re exposed to sunlight and has been linked to depression because of the role it plays in serotonin activity.

Combatting SAD symptoms

If you think you are experiencing SAD this winter, you should visit a doctor to get an accurate diagnosis. However, there are some ways you can treat SAD without medication.

• Vitamin D supplement: Taking a vitamin D supplement may help reduce your feelings of depression in the winter months. Vitamin D3 is one of the best because it is a natural form of vitamin D that you may be lacking without sunlight.
• Get sunlight in the morning: If possible, head outside for even a few minutes each day to soak in the limited sunlight. It’s best to do this earlier in the morning to help regulate your circadian rhythm and prevent sluggishness.
• Sun lamps and light therapy: Light therapy is a popular form of SAD treatment. It uses a lamp that provides bright artificial light to help your body regulate melatonin production, reduce sleepiness and improve mood. If you get one of these lamps, try sitting in front of it for 30 to 60 minutes a day.

Other ways winter can affect your mood

Not everyone who experiences the occasional winter blues is suffering from SAD. One or more of these other winter-related issues might be at the root of your shift in mood.

• Limited exercise: Cold weather can limit your ability or your desire to go outside and exercise. Fresh air and regular exercise are both known to greatly contribute to a healthier body and mind—reducing them can tank your mood. Routine exercise releases happy-hormones called endorphins and helps reduce the stress hormone, cortisol. If you’re moving less, there’s a chance you’ll start feeling “down” more often.
• Changes in diet: There’s something about the winter season that makes people abandon their nutritious diets full of veggies and balanced plates. Perhaps it’s the seemingly endless trays of fatty foods and sweets at holiday parties, or the desire to curl up on the couch with junk food on a cold wintery night. No matter what the reason, a change from a nutritious diet to a junk-filled one can leave your body lacking in important vitamins and minerals. When this happens, your systems won’t be able to function properly, leaving you feeling sluggish, tired and cranky.
• Decreased immune system: Cold weather inhibits your immune system, and being cooped up in the house every day can expose you to additional germs, meaning there’s a greater chance of you getting sick in the winter season. Even the slightest cold can make you feel tired, sore and irritable.

If you start to feel down, tired or irritable this winter, examine the lifestyle changes that may have occurred in your life due to the weather and try to change them, if possible. Remember that we need nutritious diets, routine exercise, good sleep and social interaction all year round to feel our best.