Mental Health Tips
April 26, 2024

Seasonal Affective Disorder: What It Is and What Can Help

Written by
Two Chairs Content Team
Reviewed by
Joslyn Reisinger, LMHC
Updated on
Raindrops on window with blurry green tree in background

In the United States, about 5% of adults have seasonal affective disorder (SAD). This mental health condition is a type of depression that certain seasons can trigger, with most people experiencing symptoms beginning in the fall and lasting all through the winter. 

If you suffer from SAD, understanding the condition can make a difference in treating it. At Two Chairs, we can offer guidance. 

What is seasonal affective disorder?

This condition falls under the umbrella of depression. Although many people feel a bit down during the colder months, SAD goes beyond that. Like other types of depression, it affects your energy levels, how you think and how you feel

Fall onset

The most common type of seasonal affective disorder begins in the fall and lasts until the spring. You may notice drastic mood changes as soon as the weather begins to change and there’s less daylight.

Spring onset

This is a rarer form of seasonal affective disorder. It starts in the spring and lasts through the summer until the weather cools in the fall. Some people also call it “summer depression.” 

What causes SAD?

Changes in sunlight seem to be one of the leading causes of SAD. When there’s less sunlight during the day, your biological clock shifts. Your biological clock is what regulates your hormones, sleeping patterns and moods. You may struggle to match this internal clock to the changes in daylight length. 

Changes in the season and sunlight can also affect serotonin, a brain chemical that influences mood. Because sunlight plays a huge role in regulating serotonin, and there’s less sunlight in the winter months, serotonin levels drop even more. 

Less sunlight also means less vitamin D. Vitamin D helps raise serotonin levels as well, so a lack of it contributes to symptoms of depression

Lack of sunlight can also affect your melatonin levels. Melatonin is a chemical that impacts your sleep patterns and mood. Some people experience an overproduction of melatonin when there’s less sun. 

Your risk of developing SAD increases if you are female, have a pre-existing mood disorder, reside in regions with frequent cloud cover, or have family members who have been diagnosed with the condition.

Seasonal affective disorder symptoms

For those who have fall-onset SAD, the most common symptoms are:

  • Irritation 
  • Anxiety
  • Craving carbohydrates
  • Weight gain
  • Lack of energy or extreme fatigue
  • Concentration problems
  • Oversleeping
  • Sadness
  • Loss of interest in favorite activities

Seasonal affective disorder summer symptoms can include:

  • Weight loss
  • Decreased appetite
  • Insomnia
  • Episodes of violent behavior
  • Anxiety
  • Restlessness

To be diagnosed with SAD, you have to display symptoms triggered by changes in the season for at least two consecutive years. Seasonal affective disorder tests rely on criteria defined in the Diagnostic and Statistical Manual (DSM), which therapists use to diagnose mental health disorders. A mental health professional can assess you and provide a diagnosis if applicable. 

Seasonal affective disorder treatments

Getting treatment for SAD is possible. For many people, a combination of strategies, as well as seasonal affective disorder self-care steps you can take at home, has the potential to make a difference. 


Therapy can help you manage some of the negative thoughts that lead to negative moods. One of the most effective seasonal affective disorder therapies is Cognitive-Behavioral Therapy. It helps make it easier to manage feelings of anxiety and depression by getting you to recognize unhealthy thinking patterns so you can change them. 


Seasonal affective disorder medication* can include antidepressants, which function by modulating brain chemicals like serotonin, a key contributor to mood regulation. Specifically, selective serotonin reuptake inhibitors (SSRIs) frequently prove to be particularly effective in managing the symptoms of SAD. A medical professional can talk to you about whether or not medication is right for you.

Light therapy

Seasonal affective disorder light therapy is helpful for those with fall-onset SAD. It usually requires sitting in front of a bright light box for 30 to 45 minutes daily. 

For some people with seasonal affective disorder, physical exercise can also help; exercising outdoors allows you to get more sunlight. You can combine this with using a light box. 

How to get help for seasonal affective disorder

To begin getting the care you need, you might wonder, "What kind of therapist do I need?" This is an important question to consider when turning to a mental health professional for a diagnosis. 

You can get a referral from your primary doctor, or you can use many accessible online options — like Two Chairs — that match you with a therapist you can see online, in person or both. 

Once you have a therapist, communicate your symptoms and how long you’ve experienced them. If you have SAD, you and your therapist can work together to create a treatment plan. 

Access personalized therapy with Two Chairs 

If you’ve been struggling with seasonal affective disorder, you don’t have to go through it alone. You can turn to a provider like Two Chairs for help finding the right therapist to offer guidance. Once we learn more about you and your goals and preferences for therapy, we’ll match you with a therapist so you can work towards feeling better. 

*Two Chairs does not provide psychiatric care and cannot make recommendations about medical treatments, such as medications, for mental health problems. If you want to know more about it and if it’s right for you, talk to your doctor.

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