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Introduction
Like many people, you may experience cabin fever during the winter months. Or, you may tend to eat more or sleep more when the temperature drops. But seasonal affective disorder (SAD) goes well beyond those symptoms. Seasonal affective disorder is much more than the winter blahs. It's a type of depressive disorder.
If you have seasonal affective disorder, winter's short days and long nights may induce feelings of depression, lethargy, fatigue, cravings for sweets and starches, headaches, sleep problems and irritability. Though seasonal affective disorder commonly begins in young adulthood, it's uncommon in people younger than 20. It's more common in women.
What causes seasonal affective disorder is unclear, but it may have to do with the amount of sunlight you receive. Although SAD can affect people anywhere, it becomes more common the farther north you live — perhaps because these areas of the earth experience decreased daylight for months at a time. In some people, however, recurring episodes of depression may occur in the summer, rather than in the winter.
Although there's no cure for seasonal affective disorder, treatments can help you successfully manage the condition so that you can go through every season of the year in relative comfort.
Signs and symptoms
Seasonal affective disorder is a cyclic, seasonal condition, which means signs and symptoms are present only during a particular season and then go away. Most of the time, the signs and symptoms of SAD appear during the winter and recede during the spring and summer.
There are some exceptions to the rule, however. Some people have worsened signs and symptoms of depression in the spring. Other people — less than one in 10 — experience periods of mania or hypomania, a less intense form of mania, during the summer. This is sometimes referred to as reverse SAD. Characteristics of mania may include persistently elevated mood, increased social activity, hyperactivity and unbridled enthusiasm out of proportion to the situation.
If you regularly experience the following signs and symptoms when the seasons change, you may have seasonal affective disorder:
Winter SAD
- Depression
- Anxiety
- Loss of energy
- Social withdrawal
- Increased sleep and sleepiness
- Loss of interest in activities you once enjoyed, including sex
- Overeating, especially foods high in carbohydrates
- Weight gain
- Difficulty concentrating and processing information
Summer SAD
- Anxiety
- Insomnia
- Irritability
- Weight loss
- Decreased appetite
- Increased libido
Causes
Doctors don't know the causes of seasonal affective disorder, but heredity, age and your body's chemical makeup all seem to play a role. So can the availability of sunlight.
Researchers suspect that reduced sunlight may disrupt circadian rhythms that regulate your body's internal clock, which lets you know when it's time to sleep and when it's time to wake up. This disruption may cause depression. For example, winter depression is more common in people living in more-northern latitudes, such as in Alaska, where the lengths of days and nights are more variable during the various seasons.
Some scientists have theorized that melatonin, a sleep-related hormone that's also linked to depression, might be the cause. Production of melatonin increases during the long nights of winter.
Other research suggests that lack of serotonin, a brain chemical (neurotransmitter) that seems to be triggered by sunlight, is the reason for winter depression. People who are depressed are known to have decreased levels of serotonin in their brains.
When to seek medical advice
Most people experience some days when they feel down. But if you feel down for days at a time and life seems to be losing its pleasure, see your doctor. This is particularly important if you notice that your sleep patterns and appetite have changed — and certainly so if you think about suicide.
Screening and diagnosis
It's often difficult for doctors to diagnose seasonal affective disorder because other types of depression may mimic SAD. Diagnosing seasonal affective disorder depends on whether:
- You've experienced depression and other signs and symptoms of SAD for at least two consecutive years, during the same season
- These periods of depression have been followed by nondepressed seasons
- There are no other explanations for the changes in your mood or behavior
Treatment
Like depression, it's often possible to successfully manage seasonal affective disorder. Treatments may include:
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Light therapy. This is the main treatment for many people with winter depression. In light therapy, you sit a few feet from a special lamp that's 10 to 20 times brighter than are ordinary indoor lights for 30 or more minutes each day, usually in the morning. You can do other activities, such as reading or eating breakfast, while sitting in front of the light.
Light therapy is easy to administer and has relatively few side effects. Nearly 70 percent of people experience a reduction of their symptoms from daily light therapy, and about 50 percent experience remission while undergoing light therapy. Light therapy needs to be done daily until springtime, when the sun shines for a longer period during the day. Lights from tanning beds can't be used for light therapy, because tanning beds use potentially damaging ultraviolet light.
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Medication. Your doctor may prescribe an antidepressant medication in combination with light therapy, or as an alternative, if light therapy isn't working. About 70 percent of people taking antidepressants have decreased symptoms, and about half experience remission while taking medication. Summer depression may also be treated with antidepressants.
Examples of antidepressants include paroxetine (Paxil), sertraline (Zoloft), fluoxetine (Prozac, Sarafem) and venlafaxine (Effexor). In June 2006, the Food and Drug Administration approved buproprion HCL extended release tablets (Wellbutrin XL) for prevention of depressive episodes in people with a history of SAD.
The duration of treatment with medications varies. On the basis of your history of SAD, your doctor may suggest you start medication before the time your signs and symptoms usually develop and continue the medication beyond the time the signs and symptoms usually abate. This may be from the middle of fall to the middle of spring. If you have a double depression, in which an underlying depression is complicated during the winter by SAD, your doctor may prescribe treatment with medication for a longer period.
- Psychotherapy. Psychotherapy helps you identify and modify negative thoughts and behaviors that may play a role in bringing about signs and symptoms of SAD. You and your psychiatrist or psychologist may also talk about ways to reduce stress in your life.
Coping skills
Some things you can do on your own can help you cope with seasonal depression. The following suggestions may help you better manage SAD:
- Increase the amount of light in your home. Open blinds, add skylights and trim tree branches that block sunlight.
- Get outside. Walk outdoors on sunny days, even during winter.
- Exercise regularly. Physical exercise helps relieve stress and anxiety, which can accentuate SAD. Being more fit can make you feel better about yourself.
- Find ways to relax. Learn how to better manage stress.
- Take a trip. If possible, take winter vacations in sunny, warm locations for winter SAD, or cooler locations for summer SAD.
Last Updated: 09/29/2006
