What is Seasonal Affective Disorder (SAD)?

How can the seasons affect your mood and behavior?

Seasonal Affective Disorder (also called SAD) is a type of depression that happens during certain seasons, usually starting in late fall or early winter and getting better in spring.¹

Seasonal patterns in mood and behavior are changes that happen when the seasons change, especially during fall and winter. These changes can be small, like feeling a bit more tired or eating more, or they can be big, like feeling very sad, worried, or wanting to be alone.

What causes seasonal depression?

SAD is often caused by less sunlight in the winter, which can influence your body's internal clock. It can also affect the chemicals in your brain that control mood and sleep, such as serotonin. Not getting enough vitamin D due to less sunlight can also contribute to low serotonin activity.¹

What are the symptoms of SAD?

People with SAD might experience one or more of the following feelings and symptoms:¹

• Feel very upset
• Lose interest in things they usually enjoy
• Have low energy
• Trouble sleeping or eating
• Difficulty focusing
• Feel hopeless or guilty

Who is most at risk of seasonal depression?

Anyone can get SAD, but some people are more likely to have it. Risk factors include the following:¹

• Living far from the equator, where winter nights are longer.
• Being younger in age.
• Being a woman.
• Having a family history of depression.
• Already having a mental health condition like depression or bipolar disorder.

How is SAD diagnosed?

To diagnose SAD, a doctor or therapist will talk to you about how you feel, when your symptoms start and stop, and how they affect your life. They might ask about your mood, energy, sleep, and any changes in your behavior. They will also want to know about your medical history and if anyone in your family has had similar issues.^1,3

Doctors use specific guidelines to diagnose SAD. These guidelines state that you must meet the following criteria:¹

• Have depressive episodes that start and end at the same time each year for at least two years.
• Seasonal depressive episodes happen more often than depressive episodes during other times of year.

Doctors might also use questionnaires to understand your symptoms better. Sometimes, blood tests are done to rule out other health problems that might cause similar symptoms.²

How do you treat SAD?

The best treatments for SAD often combine light therapy, talk therapy, and medicine.¹

Light Therapy

Light therapy means sitting in front of a special light box that mimics the sun. This can help your body's internal clock and boost your mood.

Talk Therapy

Talk therapy, like cognitive-behavioral therapy (CBT), can also help. CBT gives you tools to handle stress and improve your mental health.

Antidepressants

Your doctor may also prescribe antidepressant medicines called SSRIs, which help balance the chemicals in your brain that affect mood.

Lifestyle Changes

In addition to the above therapies and tools, it can be helpful to make changes in your life such as spending time outdoors during the day, exercising regularly, eating a balanced diet, and trying to reduce stress.²

How much does treatment for seasonal depression cost?

Treatment costs for SAD can vary based on what you need, such as light therapy, talk therapy, or medication. Prices range from affordable options to higher costs.

Insurance options for SAD vary depending on your plan. Many health insurance plans cover mental health services like therapy and medicine. It's a good idea to look at your insurance policy to find out what's covered and how much it costs.

When should you get help with seasonal depression?

If you feel sad most days, have difficulty doing day-to-day activities, or notice changes in your sleep or appetite, it's time to reach out for help. Talk to a doctor or mental health professional to find out how to best manage seasonal depression.

¹ Seasonal Affective Disorder, National Institute of Mental Health, Revised 2023, https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder

² What Is Seasonal Depression?, WebMD, April 30, 2024, https://www.webmd.com/depression/seasonal-affective-disorder

This information is for educational purposes only and is not medical advice. Always consult with your dentist for appropriate examinations, treatment, testing, and care recommendations.