Seasonal Affective Disorder

Seasonal affective disorder (SAD) is a depression that occurs during a particular season of the year. Most people with SAD are depressed during the fall and winter, when the days are shortest. Their depression disappears in the spring and summer. A less common type begins in late spring or early summer. Changes in the amount of daylight may be the cause of SAD.

Although many people say they get the "blues" in the winter, a person with SAD has much more difficulty coping during this season. Like other forms of depression, SAD interferes with daily life. Overcast days can make a person with SAD feel worse. People with SAD have mild to moderate depression.

SAD can affect anyone, although women are approximately 1.5 times more likely to develop SAD than are men. Those most affected are people in their late teens, 20s and 30s, with the majority women in their 30s. Older adults are less likely to develop it. It is more common in northern latitudes and extreme southern latitudes. The depression is frequently moderate to major. SAD sufferers frequently have other family members with mental illness, such as depression or alcohol abuse.

Varying levels of the neurotransmitter serotonin are believed to play a role in SAD. The sleep hormone melatonin, which has been linked to depression, also may play a role. The body makes more melatonin in the dark, so, the shorter, grayer days of winter boost levels of melatonin.

The symptoms of SAD can be confused with symptoms of other illnesses, including hypothyroidism and viral infections such as mononucleosis.

People with a mild case of SAD can ease symptoms by increasing they time they are exposed to daylight during the day. Spending time outdoors each day and getting regular outdoor exercise are two effective methods to combat SAD. For more severe cases, doctors may prescribe light therapy and possibly antidepressants. Light therapy involves exposure to very bright, full-spectrum fluorescent light for a certain amount of time each morning.

The antidepressant bupropion was approved by the Food and Drug Administration in 2006 for prevention of SAD. Treatment is started in the fall, before symptoms begin, and tapered off in the spring. An adolescent or child using bupropion should be closely monitored for suicidal thoughts and behavior.

What to Do

During the fall and winter, try to spend time outside each day. Get regular exercise, outdoors, if possible. Rearrange your furniture at home and your workspace and open the blinds or curtains to take advantage of as much sunlight in fall and winter as possible. Talk to your doctor if you have signs or symptoms of SAD significant enough to interfere with daily life. Your doctor can refer you to a mental health professional trained to treat patients with SAD.