Seasonal Affective Disorder or SAD
What is seasonal affective disorder?
Seasonal affective disorder, or SAD, is type of depression. It happens during certain
seasons of the year—most often fall or winter. It is thought that shorter days and
less daylight may trigger a chemical change in the brain leading to symptoms of depression.
Light therapy and antidepressants can help treat SAD.
Who is at risk for SAD?
SAD usually starts during adulthood. The risk of SAD increases with age. It’s rare
in people under age 20. Women are affected more often than men.
What causes SAD?
Less sunlight and shorter days are thought to be linked to a chemical change in the
brain and may be part of the cause of SAD.
Melatonin, a sleep-related hormone, also has been linked to SAD. The body naturally
makes more melatonin when it’s dark. So, when the days are shorter and darker, more
melatonin is made.
What are the symptoms of SAD?
There are two types of SAD:
- Fall-onset. This is also called "winter depression." Symptoms of depression begin in the late
fall to early winter months and ease during the summer months.
- Spring-onset. This is also called "summer depression." Symptoms of depression begin in late spring
to early summer. This type is much less common.
The following are the most common symptoms of SAD:
- Increased sleep and daytime drowsiness
- Loss of interest and pleasure in activities formerly enjoyed
- Social withdrawal and increased sensitivity to rejection
- Irritability and anxiety
- Feelings of guilt and hopelessness
- Fatigue, or low energy level
- Decreased sex drive
- Decreased ability to focus or concentrate
- Trouble thinking clearly
- Increased appetite, especially for sweets and carbohydrates
- Weight gain
- Physical problems, such as headaches
Symptoms tend to come back and then improve at about the same times every year.
The symptoms of SAD may look like other mental health conditions. Always see a healthcare
provider for a diagnosis.
How is SAD diagnosed?
Depression often happens with other conditions, such as heart disease or cancer. It
may also happen with other mood disorders, such as substance abuse or anxiety. For
these reasons, early diagnosis and treatment is key to recovery.
A diagnosis of SAD may be made after a careful mental health exam and medical history
done by a psychiatrist or other mental health professional.
How is SAD treated?
The treatments for "winter depression" and "summer depression" often differ, and may
include any, or a combination, of the following:
- Exposure to sunlight. Spending time outside or near a window can help relieve symptoms.
- Light therapy. If increasing sunlight is not possible, exposure to a special light for a specific
amount of time each day may help.
- Psychotherapy. Cognitive-behavioral or interpersonal therapy helps change the distorted views you
may have of yourself and the environment around you. It can help you improve interpersonal
relationship skills, and identifying things that cause you stress as well as how to
- Antidepressants. These prescription medicines can help correct the chemical imbalance that may lead
There are also things you can do for yourself to help relieve symptoms:
- Get help. If you think you may be depressed, see a healthcare provider as soon as
- Set realistic goals in light of the depression. Don’t take on too much. Break large
tasks into small ones, set priorities, and do what you can as you can.
- Try to be with other people and confide in someone. It is usually better than being
alone and secretive.
- Do things that make you feel better. Going to a movie, gardening, or taking part in
religious, social, or other activities may help. Doing something nice for someone
else can also help you feel better.
- Get regular exercise.
- Expect your mood to get better slowly, not right away. Feeling better takes time.
- Eat healthy, well-balanced meals.
- Stay away from alcohol and drugs. These can make depression worse.
- Delay big decisions until the depression has lifted. Before deciding to make a significant
transition—change jobs, get married or divorced—discuss it with others who know you
well and have a more objective view of your situation.
- Remember: People rarely "snap out of" a depression. But they can feel a little better
- Try to be patient and focus on the positives. This may help replace the negative thinking
that is part of the depression. The negative thoughts will disappear as your depression
responds to treatment.
- Let your family and friends help you.
Key points about SAD
- SAD is a type of depression that happens during a certain season of the year—most
often fall and winter.
- There is no clear cause of SAD. Less sunlight and shorter days are thought to be linked
to a chemical change in the brain and may be part of the cause of seasonal affective
disorder (SAD). Melatonin, a sleep-related hormone, also may be linked to SAD.
- In general, nearly everyone with depression has ongoing feelings of sadness, and may
feel helpless, hopeless, and irritable.
- SAD may be diagnosed after a careful mental health exam and medical history done by
a psychiatrist or other mental health professional.
- Depression is most often treated with light therapy, therapy, and in some cases antidepressants.
Tips to help you get the most from a visit to your healthcare provider:
- Know the reason for your visit and what you want to happen.
- Before your visit, write down questions you want answered.
- Bring someone with you to help you ask questions and remember what your provider tells
- At the visit, write down the name of a new diagnosis, and any new medicines, treatments,
or tests. Also write down any new instructions your provider gives you.
- Know why a new medicine or treatment is prescribed, and how it will help you. Also
know what the side effects are.
- Ask if your condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if you do not take the medicine or have the test or procedure.
- If you have a follow-up appointment, write down the date, time, and purpose for that
- Know how you can contact your provider if you have questions.