Medically reviewed by Katelyn Hagerty, FNP
Written by Our Editorial Team
Last updated 9/10/2022
With the changing of the seasons, you may also experience a changing of your mood.
As the days get longer, sunnier and warmer in the summer, our moods tend to get lighter and brighter as well.
Conversely, in the winter, we may notice a shift towards a more down or bluer mood — a condition known as winter blues.
The winter blues are very common, with many people experiencing mood shifts during colder, darker winter days.
But what are the winter blues exactly?
We break down what the winter blues are and what causes them, as well as strategies to handle this seasonal mood change.
The winter blues are a common mood disorder that occurs around the same time every year, typically during the fall and winter months.
Although not a medical diagnosis, winter blues certainly can affect someone’s mood and energy. When the winter blues set in, you may feel “down,” lethargic, or just not like yourself.
For some, this mood change is temporary and easily managed with lifestyle changes. But for others, the winter blues can turn into a more severe type of depression called seasonal affective disorder or SAD.
Like the winter blues, seasonal affective disorder usually only occurs during certain seasons, typically fall and winter. Unlike the winter blues, SAD is considered a form of depression.
An essential characteristic of SAD is that it follows a regular pattern — it appears during the fall and winter months, but goes away during the spring and summer months. Symptoms typically last about four to five months of the year.
The winter blues can be considered a subsyndromal (or mild version) of SAD. But these two mood disorders differ from each other in severity and function.
Feeling sad or more down than usual during the fall and winter months could signify the winter blues. But if that sadness interferes with the ability to live your everyday life, it could be SAD.
Symptoms of seasonal affective disorder may include:
Feeling hopeless or worthless
Losing interest in activities you previously enjoyed
Problems sleeping, such as oversleeping (hypersomnia)
Changes in your appetite, such as overeating or eating less
Social withdrawal, or feeling like “hibernating”
Having thoughts of death or suicide
While SAD may have more severe symptoms than winter blues, both have very similar causes.
Seasonal affective disorder and winter blues can both be caused by a few different factors.
The farther someone lives from the equator, the higher their risk of developing winter blues or SAD.
In northern parts of the United States, residents are more likely to be affected by seasonal affective disorder due to winter days lasting longer than in southern parts.
People who live in cloudy regions could also be at higher risk for winter blues and SAD.
With less daylight, as well as less time spent outdoors, our bodies produce less vitamin D in fall and winter.
Vitamin D is present in certain foods, and is also produced by our cells when our skin is exposed to ultraviolet (UV) rays from sunlight.
It’s unclear why, but many people with winter blues and seasonal affective disorder have a vitamin D deficiency.
The decrease in exposure to sunlight during the winter can also affect our circadian rhythm, our bodies' natural process that regulates the sleep-wake cycle and responds primarily to light and dark.
Your risk of developing the winter blues or SAD also increases if you have relatives with SAD or other forms of depression or mental health conditions.
Those with winter blues or seasonal affective disorder have difficulty regulating the neurotransmitter serotonin, a brain chemical believed to be responsible for balancing feelings, mood and thoughts, as well as regulating happiness and anxiety.
In one small study, people with seasonal affective disorder had more SERT, a protein that assists with transporting serotonin, in the winter months than in summer. Higher SERT levels lead to lower serotonin levels, causing depression.
An increase in melatonin production may also be a cause of winter blues.
Melatonin, a hormone produced in response to darkness, helps regulate the timing of your circadian rhythms and sleep.
As darker winter days come around, some people may produce more melatonin. This can make those with winter blues or SAD feel more lethargic or tired.
Treatment options for the winter blues are similar to treatments for seasonal affective disorder, although not exactly the same.
For example, since the winter blues is milder and usually lasts for less time, you would not be prescribed medication to treat it, but people with SAD may be prescribed medications like selective serotonin reuptake inhibitors (SSRIs).
So, read on for tips and strategies to help manage the winter blues.
One of the main treatments for winter blues and seasonal affective disorder is light therapy.
Researchers at the National Institutes of Health (NIH) first linked light with seasonal depression back in the 1980s.
As the days grow darker and we spend less time outside in the winter, our bodies have less exposure to the sunlight necessary for producing vitamin D and managing melatonin. Both of these affect the circadian rhythm, which affects our energy levels and how tired we feel.
Light therapy — also known as bright light therapy (BLT) or phototherapy — uses bright, artificial light, particularly in the morning, to replicate sunlight. Those affected by winter blues or seasonal affective disorder sit in front of a light box for up to 60 minutes every morning during the fall and winter months.
Multiple studies have shown that light therapy relieves SAD symptoms for as many as 70 percent of patients after a few weeks of treatment.
Side effects of light therapy are usually not severe, but they are still possible. Side effects may include:
Increased risk of blurred vision, especially as you age
Our guide on sunlamps for depression goes over the details of how light therapy works and the benefits.
Therapy is another effective treatment for winter blues and SAD.
Cognitive-behavioral therapy (CBT) is a form of therapy often used to treat types of depression and other mental disorders, including seasonal affective disorder and winter blues.
CBT focuses on identifying unhealthy and disordered thoughts that fuel negative emotions and behaviors and learning to correct them.
One study of 177 adults diagnosed with SAD discovered that six weeks of CBT was just as effective as 30 minutes of daily light therapy.
If you’re experiencing winter blues or seasonal depression and think you could benefit from therapy, you can talk to a mental health professional online to find a solution for your symptoms.
Stress can lead to experiencing the winter blues. And whether you’re dealing with upcoming family visits, preparing for the holidays, missing loved ones or trying to wrap things up at work, winter can be a busy and stressful time of year for many.
Vitamin D can play an important role in winter blues and seasonal affective disorder. As of 2018, 42 percent of adults in the U.S. are deficient in vitamin D.
Include more foods high in vitamin D — such as fatty fish, fish oil and vitamin D fortified foods like milk, orange juice, mushrooms, yogurt and fortified cereal — into your diet to help balance your mood.
You can also talk to your healthcare provider to see if taking a vitamin D supplement is the right choice for managing your winter blues.
Physical activity has been shown to boost mood, decrease symptoms of depression and reduce stress.
If it gets darker outside earlier in the winter, try to take short walks throughout the day to break up exercise. Instead of one 30-minute walk, try taking three 10-minute walks in the morning, at lunch and before the sun goes down.
The winter blues can take a toll on your physical and mental health. But while you can’t change the season, you can make choices to help minimize the effects of feeling down.
If lifestyle changes are not providing enough relief, it may be time to schedule an appointment with your healthcare provider or a licensed therapist to determine if you’re dealing with the winter blues or SAD.