Seasonal Affective Disorder (SAD)

What is seasonal affective disorder?

SAD is depression that affects some people during the winter. People who have SAD begin to feel depressed in the late fall and then feel much better as spring arrives. In the northern hemisphere, January and February are usually the months with the greatest symptoms.

How does it occur?

Seasonal affective disorder (SAD) usually comes on gradually during fall each year. It seems to lift much faster in the spring than it begins in the fall. More people experience SAD the further north they live. In the northern United States up to 25% of people report some features of SAD. Only 2 or 3% of people are severe enough to need treatment. Women are more likely to develop SAD. It usually begins during the young adult years and continues throughout life.


What causes SAD is unclear. There are several theories about hormone and brain patterns and the amount of sunlight received through the eyes and skin. To date, none of the theories fully explains SAD. We do know that exposure to light is linked to certain natural rhythms in the body. These are called circadian rhythms. These rhythms regulate body changes such as changes in mood.

What are the symptoms?

The symptoms of SAD are more specific and somewhat different from other depressions. If you have SAD, in the fall you are likely to:

  • Feel uninterested in doing usually fun things
  • Have an increased appetite with a craving for foods with starch (like potatoes and bread).
  • Gain weight.
  • Have trouble getting up in the morning and often want an afternoon nap.
  • Feel tired and slowed down much of the time.
  • Have lower sexual desire and function.
  • Have trouble concentrating.
  • Have worse than usual premenstrual symptoms if you are a woman.

When spring arrives each year, you are likely to feel a "high" and have a rush of energy. For a few people, the springtime "high" borders on mania. These symptoms must be a pattern for at least 2 years before they are considered seasonal affective disorder.

How is it diagnosed?

Your health care provider or a mental health professional can tell you if your symptoms are seasonal affective disorder. He or she will ask about your symptoms, history and any drug or alcohol use. You may be asked to have some lab tests to rule out medical problems such as hormone imbalances. There are no lab tests to diagnose seasonal affective disorder.

How is it treated?

The most effective treatment for SAD is increasing exposure to sunlight or artificial light that is like sunlight. Treatment for depression, such as medicine and psychotherapy, are also helpful.


Light Therapy


Special fluorescent light bulbs that imitate sunlight are used. These are up to 25 times as bright as normal fluorescent bulbs. Such bulbs range in the amount of light (measured in lux) from 2,500 to 10,000 lux. For treatment, you should be about three feet from the light. If a 2,500 lux source is used, then you should be in the light for 2 hours or more. If 10,000 lux is used, then around 30 minutes. It is best to use the lights in the morning. The light helps with waking up in the morning. It also lessens the desire for a nap. For some, using the lights in the evening causes trouble with getting to sleep. You do not need to expose a lot of skin to the light.


Medicine


Antidepressant medicines can help treat seasonal affective disorder. Your health care provider will work with you to select the best medicine for your symptoms.


You must take antidepressant medicines daily for 3 to 6 weeks to get full benefit from them.


There are no nonprescription medicines available to treat seasonal affective disorder.


Psychotherapy


Seeing a psychologist, psychiatrist, or psychotherapist in addition to light therapy may be helpful with seasonal affective disorder. Therapy may last a short time or may need to go on for many months. Cognitive behavioral therapy (CBT) is a form of psychotherapy that is especially helpful. CBT is a way to help you identify and change thought processes that lead to depression. Replacing negative thoughts with more positive ones can help your depression. Interpersonal therapy may also be very helpful.


Complementary Treatments


Diets rich in fruits and vegetables are recommended for people with depression. A multivitamin and mineral supplement may also be recommended.


Studies suggest that eating fatty fish 2 to 3 times per week may reduce feelings of depression and anxiety. These fish contain omega-3 polyunsaturated fatty acids. Fatty fish include salmon, tuna, mackerel, herring, and sardines. For people who dislike fish, flaxseed, pumpkin seed, walnuts, and olive oil are also sources of omega-3 fatty acids. Fish oil supplements are available.


Taken in appropriate doses, St. John's wort may help with some forms of mild depression. It does not help with severe depression, and may cause side effects, such as sun sensitivity, anxiety, or sleeplessness.


Other supplements that may be helpful in treating depression include SAMe, DHEA, and 5-hydroxytryptophan.


Be careful which products you use. "Natural" products are not standardized. They may have different strengths and effects. Some may be contaminated. Herbs and supplements affect your body and may interact with prescription medicines. Talk to your health care provider or pharmacist about any supplements that you are using or considering.

How long will the effects last?

Usually seasonal affective disorder is a lifelong condition. For this reason, you should seek professional help. The treatments listed above most often will help you to overcome SAD or at least reduce it.

What can I do to help myself or my loved one?

Maintaining a healthy lifestyle is crucial to helping to control seasonal affective disorder. Staying physically and socially active is very important. Maintaining regular sleep and eating patterns will also help you.


To help prevent or reduce the effects of seasonal affective disorder:

  • Between fall and spring get outside or near a window frequently each day.
  • Exercise for at least 20 minutes every day, for example a brisk walk.
  • Learn which activities make you feel better and do them.
  • Talk to your family and friends.
  • Eat a healthy diet with a low amount of starch (found in potatoes and bread).
  • Do not drink a lot of caffeine.
  • Do not abuse alcohol or drugs.
  • Learn ways to lower stress, such as breathing and muscle relaxation exercises.

When should I seek help

Seek professional help if you have symptoms that keep you from doing daily tasks such as work and family responsibilities.


Get emergency care if you or a loved one have serious thoughts of suicide or harming others.


Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.


HIA File BHV3357F.HTM Release 9.0/2006

Copyright © 2006 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.

Copyright © 2006 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.