Seasonal Affective Disorder: Signs and What Helps
As the days get shorter, many people feel more tired and a little low. For some people, the change is much bigger. Their mood drops every fall or winter, it affects daily life, and it lifts again in spring. This pattern has a name: seasonal affective disorder, or SAD.
This article explains the signs of SAD, who is more likely to get it, and which treatments have good evidence. In the United States, clocks go back one hour on the first Sunday of November, and the darker evenings that follow are a common trigger for low mood.
Medical Disclaimer
This article is provided for general educational and informational purposes only and does not constitute medical advice, diagnosis, or treatment. While the content is written with input from a licensed healthcare professional, reading this article does not create a nurse-patient, provider-patient, or any other professional relationship between you and the author or Vida Atlas.
The information here is general in nature and is not a substitute for personalized medical advice from your own doctor or qualified healthcare provider, who can take your full medical history and individual circumstances into account. Always consult your doctor or another qualified healthcare provider with any questions you may have regarding a medical condition, and never disregard professional medical advice or delay seeking it because of something you read on this site.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency room immediately. Do not rely on this article for urgent or emergency medical situations.
Vida Atlas and the author make no representations or warranties about the accuracy, completeness, or timeliness of the information provided, and disclaim liability for any actions taken or not taken based on the content of this article.
Quick Answer
Seasonal affective disorder is a form of depression that returns at the same time each year. The National Institute of Mental Health (NIMH) says the symptoms last about four to five months of the year (1). It is most often a winter pattern. Light therapy, talk therapy, and antidepressant medicine can all help, so it is worth speaking to a doctor if your mood drops every year.
Winter Blues or SAD?
Feeling a little slower or sadder when the days get short is common, and it is not a disorder. SAD is different because it is a type of depression. The NIMH lists low mood, hopelessness, irritability, guilt, loss of interest, and low energy among the symptoms, and says not every person has all of them (1). The key sign is the pattern: the symptoms come back in the same season year after year.
If your low mood lasts all year, or it does not lift in spring, the cause may be a different type of depression. You can read about it in What Is Depression?. If you are not sure whether your tiredness is low mood or burnout, Burnout or Depression? may help.
Signs of Winter-Pattern SAD
Besides the general signs of depression, the NIMH describes three features that are common in the winter pattern (1):
- Sleeping too much.
- Overeating, especially craving carbohydrates, which can lead to weight gain.
- Pulling away from other people, which the NIMH compares to feeling like you are hibernating.
A less common summer pattern also exists, but winter-pattern SAD is more common (1). Poor sleep can be part of the picture too. If you often wake in the night, see Why Do I Wake Up at 3 AM Every Night?.
Who Is More Likely to Get SAD
The NIMH says SAD happens much more often in women than in men, and it usually starts in young adulthood (1). It is also more common in northern areas with short winter days, such as Alaska and New England. It can run in families, and it is more common in people who have relatives with other mental illnesses (1).
What Helps
Light Therapy
Light therapy is used mainly for winter-pattern SAD. The NIMH describes a very bright light box of 10,000 lux used for about 30 to 45 minutes a day, usually first thing in the morning (1). Cleveland Clinic describes light boxes of 2,500 to 10,000 lux used for about 20 to 30 minutes (2). The time depends on the strength of the lamp, so follow the instructions on your device.
Cleveland Clinic advises placing the box 16 to 24 inches away, off to the side, and not looking straight into the light (2). Side effects can include headaches, blurry vision, tiredness, and eye strain. Talk to a healthcare provider first if you have an eye condition, are sensitive to light, take certain medicines, or have bipolar disorder (2).
Talk Therapy
The NIMH describes a form of cognitive behavioral therapy made for SAD, often given as two weekly group sessions for six weeks. In one study, light therapy and this type of therapy worked about equally well. A long-term follow-up found that the benefits of therapy seemed to last longer (1).
Medicine and Vitamin D
Antidepressants can help, alone or together with therapy. They usually take four to eight weeks to work. The FDA has approved extended-release bupropion to help prevent seasonal episodes from coming back (1). The NIMH adds that studies of vitamin D have had mixed results, so its benefit is uncertain (1).
Daily Habits for the Darker Months
Good habits do not replace treatment, but they can support it. The Sleep Foundation notes that studies link the autumn and spring clock changes to a higher risk of mood problems. For most people the effects fade within days or weeks (3). These steps can help your body adjust:
- Spend time outdoors in the morning, because natural light helps reset your body clock (3).
- Keep the same sleep and wake times, including on weekends (3).
- Avoid alcohol close to bedtime (3).
- Plan something to look forward to each week, such as a walk with a friend.
When to See a Doctor
Make an appointment if low mood returns every year, lasts for weeks, or affects work, school, or relationships. A doctor can check for other possible causes and talk with you about treatment. How to Know If You Need Therapy explains signs that it may be time to talk to a professional.
If you have thoughts of suicide, call or text 988 to reach the 988 Suicide and Crisis Lifeline, or chat at 988lifeline.org (1). In a life-threatening emergency, call 911.
Conclusion
Seasonal affective disorder is real, it is common, and it is treatable. Because the pattern repeats every year, you can plan ahead. Light therapy, talk therapy, and medicine are all options, and a doctor can help you choose. If you notice your mood dropping as the days shorten, getting help early may make the season easier.
