Do I Have Seasonal Affective Disorder? Signs And Symptoms

Medically reviewed by April Justice, LICSW
Updated February 22, 2024by BetterHelp Editorial Team

Have you experienced notable changes in mood during certain times of year, especially winter? If so, you are not alone. According to the American Psychiatric Association, approximately 5% of people in the United States experience seasonal affective disorder (SAD). More than just sadness in winter, SAD is a serious depressive disorder that can produce a variety of concerning symptoms, such as low mood, lack of energy, and loss of interest in activities once enjoyed. Despite these challenges, seasonal depression can be managed with the right approach. Below, we’ll look at seasonal affective disorder, its symptoms, and how it can be treated. 

You can manage seasonal depression with the right support

Overview of seasonal affective disorder

For many people, the variations in weather and sun exposure that often accompany seasonal changes can have an impact on their mood. If you feel sad, tired, or just different as fall and winter approach, it might be more than just the blues, though. You may be experiencing symptoms of SAD—also called seasonal depression—one of several different depressive disorders.

Unlike other forms of depression, seasonal affective disorder doesn’t usually last throughout the year—instead symptoms typically arise during months in which cold weather and a lack of sun are common.

It can be easy to miss a diagnosis of SAD because people with the condition may not experience symptoms for most of the year. If this sounds like something you’re experiencing, a mental health professional may be able to provide a proper diagnosis and treatment.

Differences between SAD and major depression

What can be confusing about seasonal affective disorder (SAD) is that it is considered a form of major depressive disorder (MDD). The Diagnostic and Statistical Manual of Mental Disorders (DSM-V) lists seasonal affective disorder as “Major Depressive Disorder with Seasonal Pattern”. The primary difference is that seasonal depression often starts and stops at specific times, and major depressive disorder, without a seasonal pattern tends to last all year. The symptoms, however, are often the same. 

One potential difference between seasonal depression and major depression is the way in which emotional symptoms arise. People with seasonal depression may feel more sad than irritable or angry, which are common signs of major depression without a seasonal component. There can also be differences in physical symptoms. An individual with SAD may sleep longer than normal and develop an increased appetite, instead of experiencing insomnia and a decrease in appetite. 

Signs and symptoms of seasonal affective disorder

The DSM criteria for a diagnosis of major depressive disorder with seasonal pattern includes experiencing “depression that begins and ends during a specific season every year (with full remittance during other seasons) for at least two years and having more seasons of depression than seasons without depression over a lifetime”. 

The National Institute of Mental Health (NIMH) lists the following symptoms of seasonal affective disorder:

  • Lack of energy
  • Excessive sleepiness
  • Eating more than normal
  • Gaining weight
  • Craving carbohydrates
  • Withdrawing socially
  • Weight loss associated with lack of appetite
  • Insomnia
  • Feelings of irritation or agitation
  • Restlessness
  • Anxiety
  • Unusual violent behavior
  • Suicidal ideation

If you or a loved one is experiencing suicidal thoughts, reach out for help immediately. The 988 Suicide & Crisis Lifeline is available 24/7 and can be reached by calling or texting 988 or chatting with a representative, and it’s available 24/7.

Many people with seasonal affective disorder find that their symptoms appear around fall or early winter, then wane or disappear completely around spring or early summer. That’s not to say that someone can’t experience symptoms at all during the warmer months. A few weeks of rainy, gloomy days during the summer might cause symptoms of SAD to emerge. Many people, though, find that their symptoms do not return during warmer seasons.


Treatment for SAD

Treatment for seasonal affective disorder can help an individual understand the source of their feelings, improve their mood, and find ways of enjoying the cold weather months. The following are proven treatment options for managing the symptoms of SAD. 

Light therapy

Because the dark days of winter tend to bring about symptoms of seasonal affect disorder (SAD), exposure to light can have a positive effect on the disorder. Research suggests that bright light therapy—in which participants expose themselves to artificial light or sunlight—can effectively reduce the symptoms of seasonal depression

Light therapy dates back to the 1980s, when SAD was first described as a mental health condition. It typically relies on boxes that emit strong light. When the sun doesn’t shine as often in the fall and winter seasons, exposing oneself to bright, artificial light may significantly improve the symptoms of SAD. It is thought that light therapy either works by controlling an individual’s circadian rhythm or increasing serotonin levels. 

A common light therapy treatment consists of sitting in front of a lightbox first thing in the morning. Many lightboxes produce 10,000 lux of cool-white fluorescent light and emit up to 20 times more light than regular indoor lighting. If you’re experiencing seasonal affective disorder, a healthcare professional can help you develop a treatment plan that may include light therapy. 

Vitamin D supplements

There is a correlation between low levels of vitamin D and symptoms of seasonal affective disorder. Vitamin D—which is important to your immune health and other vital functions—may be difficult to obtain in the absence of sun. For this reason, vitamin D supplements are often incorporated into treatment plans for SAD. Studies have confirmed the potential efficacy of vitamin D for SAD symptoms, with researchers in one trial finding that it was more effective than light therapy


Certain antidepressants, including selective serotonin reuptake inhibitors (SSRIs), have been shown to decrease symptoms of seasonal affective disorder. These medications often work by increasing serotonin levels, which are often deficient in people with depressive disorders. Always consult with a healthcare professional before starting or stopping any medication. 


Many people who live with seasonal affective disorder experience improvement after seeing a therapist. One common type of psychotherapy for seasonal affective disorder is cognitive behavioral therapy (CBT). A therapist may use CBT to help you identify negative thoughts and replace them with more positive thoughts—in connection with another therapeutic technique called behavioral activation. For example, your therapist might help you reframe negative thoughts about cold weather that may be underlying sadness or a lack of energy. Then, the behavioral activation component might enable you to identify activities that you can enjoy inside or outside to help you cope with the winter.

Causes of SAD

Researchers haven’t been able to figure out conclusively why some people get seasonal affective disorder and others don’t. Disruptions in an individual’s circadian rhythm, which often occur with changes in light exposure, are thought to play a role. These disruptions may be partly due to alterations in melatonin levels, which can make you feel listless and tired.

There is also evidence that specific populations of people tend to be more at risk for SAD than others. Surveys and studies have shown that women are four times more likely to experience SAD than men are. And younger adults are more likely than older adults to develop the condition. People who work evening shifts are also considered to be at a greater risk for experiencing seasonal depression. 

Individuals who live far north or south of the equator, where climates tend to be colder, may also be more prone to symptoms of seasonal affective disorder. Researchers in one study found that 1% of Florida residents experienced SAD, compared to 9% of residents of New England and Alaska.

Experts also believe that people with a family history of other types of depression may be at greater risk for SAD—and that people who have already been diagnosed with depression or bipolar disorder may have worse symptoms in the colder months. 

As noted earlier, people with SAD may have low levels of vitamin D. Vitamin D is connected to serotonin, a chemical in your brain that helps control mood. Research shows that people with seasonal depression have increased levels of serotonin transporter, also called 5-HTT, which can reduce the amount of serotonin available.

You can manage seasonal depression with the right support

How online therapy can help

Research suggests that cognitive behavioral therapy (CBT) is the most effective form of treatment for seasonal depression. Online therapy platforms give opportunities to providers who practice CBT, and studies show that this form of care is efficacious when managing a variety of depressive symptoms. In one wide-ranging review, researchers concluded that online therapy is both time-efficient and cost-effective when treating depressive disorders

As noted above, therapy can be a core component of a treatment plan for relieving symptoms of seasonal affective disorder. If you aren’t feeling well enough to leave home due to seasonal depression or similar concerns, you might try online therapy. With an online therapy platform like BetterHelp, you can talk to a licensed therapist from home, through video call, voice call, or in-app messaging. You’ll also have the opportunity to reach out to your therapist between sessions, allowing you to ask questions or clarify points made about seasonal depression. 


Seasonal affective disorder is a form of depression that can seriously impact an individual’s emotional health and ability to function. If you think you may be experiencing symptoms of seasonal affective disorder, know that there are treatments available. You may benefit from talking to a licensed therapist, who can help you develop evidence-based strategies for improving your mental health in the winter. With opportunities for the right support and resources, you can manage symptoms of seasonal depression and flourish regardless of the season.
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