Winter Blues vs. Seasonal Affective Disorder

Sad man depressed in his room

Vasily Pindyurin / Getty Images

During the winter months, the later sunrise, earlier sunset, and cloudiness limit the amount of sunshine to which we're exposed. For example, you might commute to and from work in the dark after working indoors all day. In fact, if you dislike cold-weather activities, you might not see sunlight for several days at a time.

This can result in a mood commonly called the winter blues. If this sadness affects your ability to function, however, it might be a clinical condition known as seasonal affective disorder (SAD).

Winter Blues
  • Not a clinical diagnosis

  • Doesn't interfere with daily functioning

  • Feelings of sadness

  • Limited to winter months

  • Managed with lifestyle changes

Seasonal Affective Disorder
  • Condition classified by DSM

  • Interferes with daily functioning

  • Depression

  • Can occur in summer

  • May require medication and/or therapy

What Are the Winter Blues?

Winter Blues

The winter blues describe the sadness and fatigue that many people experience during the coldest, darkest months of the year.

If you have the winter blues, you might find getting out of bed difficult on some mornings. You might have trouble sleeping and feel generally unmotivated to complete daily tasks or get outside. However, the winter blues are temporary and don't affect your ability to complete necessary, day-to-day tasks.

Simply put, the winter blues are temporary, common, and require no treatment. In contrast, SAD is described in the Diagnostic and Statistical Manual of Mental Conditions (DSM-V) as a major depressive disorder with a seasonal pattern.

Symptoms of the Winter Blues

Although winter blues aren't considered a mental health disorder and don't interfere with daily functioning, you might:

  • Feel sad during the winter months
  • Lack the motivation to complete some tasks but be able to handle major tasks such as going to work and taking care of the house
  • Have trouble sleeping
  • Spend more time in bed than usual

Treatment for the Winter Blues

Lifestyle changes and self-care routines are key to improving your mood in the winter months. Here are a few strategies to beat the winter blues.]

Seek Out the Sun

The sun is an unlimited source of vitamin D, which is essential for circadian rhythm regulation. Sunlight exposure can help increase energy levels and boost mood. If winter features a lot of snow, rain, and cloudiness during the winter, consider traveling to a sunny tropical place to reset your clock and soak up the warm rays.

Adopt a Regular Sleep/Wake Routine

Going to bed at the same time every night and waking up at the same time every morning can help stabilize your internal clock and allow you to wake up feeling refreshed and energized instead of feeling fatigued throughout the day.

Exercise Daily

Exercise releases endorphins, which are known to improve mood and energy. Exercising at least 30 minutes each day for five days a week can improve your energy levels and mood.

Exercising outdoors is even better as it allows you to breathe in the fresh air, soak up the sun and enjoy nature.

Eat a Balanced Diet

In the winter, many of us crave sweets and complex carbohydrates, which can leave us feeling tired. Try to incorporate whole grains and fresh produce into your diet on a daily basis.

Try eating foods that are rich in vitamin D such as fish, egg yolks, mushrooms and foods such as milk, juices and cereals that are fortified with vitamin D.

Consider Vitamin D Supplements

Winter's lack of sunlight can deplete your vitamin D stores. In turn, this can make symptoms worse. Although it is best to obtain your daily dosage of vitamin D from diet and sunlight, taking daily vitamin D supplements may be the best way to improve your mood during the winter months.

The recommended daily vitamin D intake ranges from 10 to 20 mcg per day, depending on age. An estimated 40% of U.S. adults are deficient in vitamin D.

Stay Connected With Friends

A healthy social support system is important to feel connected and to get you out of the house during the long winter months. Whether it is cooking, skiing, or a night out on the town, spending time with friends and loved ones can help boost your mood in addition to having someone to talk to about your feelings.

What Is Seasonal Affective Disorder?

Seasonal Affective Disorder

Seasonal affective disorder (SAD) also known as seasonal depression is a mental health disorder characterized by distressing and overwhelming feelings of sadness that can interfere with daily functioning.

The Diagnostic Manual of Mental Disorders (DSM-5) identifies SAD as major depressive disorder (MDD) with a seasonal pattern. Symptoms of SAD range from mild to debilitating. It can occur anytime during the year and isn't tied to seasonal change.

SAD typically becomes apparent in autumn, peaks in winter, and resolves in spring. Its incidence is highest in the Pacific Northwest and the Northeast, where gray skies dominate for four to six months of the year.

SAD Can Appear in the Summer Months

Seasonal affective disorder is most prevalent during the winter months and when we think of SAD, we think of cold, dark winter days; however, SAD also appears in the summer, but at a much more rare occurrence.

According to research, "A small share of people with SAD show the reverse pattern, being sensitive to summer's longer days. The very existence of opposite winter-summer patterns suggested to researchers that this mood disorder stems from a problem in adapting to the physical environment."

SAD Statistics

  • SAD is estimated to affect 10 million Americans
  • SAD is four times more common in women than in men
  • The age of onset for SAD is estimated to be between the age of 18 and 30 and rarely affects people younger than 20 years of age
  • The incidence of SAD decreases as the individual ages
  • Six percent of individuals with SAD require hospitalization

Symptoms of SAD

  • Overeating
  • Craving foods that contain complex carbohydrates
  • Weight gain
  • Difficulty sleeping
  • Depressed mood most of the day, nearly every day
  • Loss of interest in activities you typically enjoy
  • Withdrawal and isolation from loved ones
  • Inability to focus and concentrate on work performance and household tasks
  • Lethargy and fatigue
  • Hopelessness
  • Suicidal thoughts

Note: To be diagnosed with SAD, your symptoms must interfere with your daily functioning.

Causes of SAD

Changes to our internal clocks and hormones fluctuation both contribute to SAD. The main causes of SAD are listed below.

Circadian Rhythm

Our body’s internal biological clock—circadian rhythm—drastically changes when winter approaches. The decrease in daily sunlight over a long period of signals to our body that it is nighttime which leads to fatigue throughout the day.


Serotonin is a chemical in the brain that plays a large role in mood regulation. Serotonin is also the primary ingredient in selective serotonin reuptake inhibitors (SSRIs), the first-line (i.e., primary) treatment for moderate to severe depression.

Individuals with seasonal affective disorder have lower levels of serotonin. Brain imaging studies such as MRIs and CTs have shown individuals with seasonal depression to have higher levels of serotonin transporter proteins. These transporter proteins, "transport" serotonin out of the brain, therefore lowering the levels of serotonin in these individuals with seasonal affective disorder.

Selective serotonin reuptake inhibitors (SSRIs), increase the level of serotonin in the brain by preventing its reuptake and destruction. As a result, SSRIs are used for individuals with seasonal affective disorder to help boost serotonin levels and improve mood.


Melatonin is a specific sleep hormone that is stored and released by the pineal gland in the brain. Melatonin is responsible for sleep patterns and plays a crucial role in circadian rhythm regulation and therefore highly affects mood.

Darkness stimulates the production of melatonin, preparing the body for sleep. As a result, melatonin is produced at higher levels when the days are shorter and darker, resulting in feelings of fatigue throughout the day.

Vitamin D

Vitamin D is produced in our body from both sunlight and our dietary intake. When sunlight is greatly reduced due to the decreased length of daytime in the winter, our body’s supply of vitamin D becomes depleted.

Vitamin D is believed to play a role in the regulation of serotonin. Therefore, insufficient levels of vitamin D can contribute to feelings of depression.

Treatment For SAD

“Once SAD was identified, researchers hypothesized that its typical appearance with winter had something to do with lowered exposure to sunlight. The obvious next step was to lengthen exposure to light intensity more akin to outdoor levels; it worked."


Antidepressants, particularly SSRIs, are the medication of choice in the treatment of SAD.

Examples include citalopram, fluoxetine, escitalopram, sertraline, and paroxetine. SSRIs take approximately four to six weeks to work, and some side effects may include decreased libido and weight gain.

The FDA has approved another antidepressant, known as bupropion, to treat SAD. Bupropion is a second-line medication (i.e., medication that is prescribed if the primary treatment is ineffective) and is used to treat those dealing with SAD who could not tolerate SSRIs.

Light Therapy

Light therapy, also known as phototherapy, is considered the first-line treatment for individuals with SAD.

A light therapy box mimics outdoor light by emitting as little UV light as possible. Researchers believe this type of light causes a chemical change in the brain that lifts your mood and eases other symptoms of SAD.

Light therapy and melatonin have been shown to improve signs and symptoms associated with SAD because they affect our circadian rhythms at different times of the day. For example, administering light therapy in the morning upon waking up and taking melatonin a few hours before bedtime has been shown to help regulate our circadian rhythm.

There are specific light boxes that are used to treat various conditions:

  • Light boxes to treat SAD filter out ultraviolet (UV) light
  • Light boxes that treat skin disorders use UV light (and could potentially damage your eyes if used incorrectly)

A special light box that gives off 10,000 lux of fluorescent light, more than 20 times brighter than most indoor light, increases serotonin in your brain, a neurotransmitter that is responsible for mood.

Light boxes for SAD can be purchased without a prescription and can be used in all indoor settings such as the home or office. Some light boxes resemble lamps while others resemble rectangular boxes.

They average cost for this kind of light box is $75, and bulbs should be replaced every two to three years. If you have SAD, remember to always keep your light box handy during the winter months.

Buying and Using a Light Box

If you're in the market for a light box to help lessen your symptoms of SAD, the light box you choose should provide an exposure of 10,000 lux of light and emit as little UV light as possible.

After purchasing a light box, keep the following recommendations in mind when you begin to use it:

  • Use it within the first hour of waking up in the morning for about 20 to 30 minutes
  • Keep the light box at a distance of about 16 to 24 inches (41 to 61 centimeters) from your face
  • You can keep your eyes open but do not look directly at the light

By following these tips, you should start to see an improvement in your symptoms within one to two weeks.

Dawn Simulators

Studies have shown that dawn simulators are equivalent to light box therapy for the treatment of SAD. Dawn simulators work as an alarm clock but replace the gradual intensity of a bedside light instead of giving off a loud, jarring beeping noise.

These devices gradually increase the strength of the light over 30 to 60 minutes during the early morning awakening process, simulating early morning dawn.

This gradual increase in light reaches the retina through your translucent eyelids, and by the time the individual is awake, the treatment has subsided.

Lifestyle Modifications

Making changes to your routine can be used to alleviate the symptoms of SAD and the winter blues.

But, when treating SAD, these lifestyle changes must be used in addition to other treatment options including light therapy and antidepressants. On the other hand, people who are experiencing winter blues can benefit from lifestyle modifications and self-care routines alone.

3 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institutes of Health. Office of Dietary Supplements: Vitamin D Fact Sheet for Health Professionals.

  2. National Institutes of Health. Office of Dietary Supplements: Vitamin D Fact Sheet for Health Professionals.

  3. American Psychological Association. Bright lights, big relief: treating seasonal affective disorder.

By Kristen Fuller, MD
Kristen Fuller is a physician, a successful clinical mental health writer, and author. She specializes in addiction, substance abuse, and eating disorders.