Seasonal Affective Disorder - Seasonal Affective Disorder (SAD)

Seasonal Affective Disorder (SAD)

What is seasonal affective disorder?

Seasonal Affective Disorder (SAD) is a type of depression that is triggered by the seasons. The most common type of SAD is called winter-onset depression. Symptoms usually begin in late fall or early winter and go away by summer. A much less common type of SAD, known as summer-onset depression, usually begins in the late spring or early summer and goes away by winter. SAD is related to changes in the amount of daylight during different times of the year.

How common is SAD?

As many as half a million people in the United States may have winter-onset depression. Another 10% to 20% may experience mild SAD. SAD is more common in women than in men. Although some children and teenagers get SAD, it usually doesn't start in people younger than 20 years of age. For adults, the risk of SAD decreases as they get older. Winter-onset SAD is more common in northern regions, where the winter season is typically longer, more harsh, and there are less hours of daylight.

What are the symptoms of SAD?

Although your symptoms are clues to the diagnosis, not everyone who has SAD experiences the same symptoms. Common symptoms of winter-onset SAD include the following:

Change in appetite, especially a craving for sweet or starchy foods
Weight gain
Drop in energy level
Fatigue
Tendency to oversleep
Difficulty concentrating
Irritability and anxiety
Increased sensitivity to social rejection
Avoidance of social situations and a loss of interest in the activities once previously enjoyed

Symptoms of summer-onset SAD include:

Loss of appetite
Weight loss
Insomnia
Irritability and anxiety
Agitation
Increased sex drive

Either type of SAD may also include some of the symptoms that are present in other forms of depression. These symptoms include feelings of guilt, ongoing feelings of hopelessness, and physical problems (such as headaches).

Symptoms of SAD return every year. They also tend to come and go at about the same time every year. The changes in mood are not necessarily related to obvious things that would make a certain season seem stressful (such as seasonal unemployment during the winter months).

Is there a treatment for SAD?

Yes, treatment is available for SAD. Winter-onset SAD is most likely caused by your body's reaction to the lack of sunlight. Light therapy is one option for treating this type of SAD because increased exposure to sunlight can improve symptoms.

If your doctor suggests that you should try light therapy, you will want to purchase a special-made light box that emits 10,000 lux of intense light. Generally, 30 minutes of light therapy is required each day throughout the fall and winter, when you are most likely to be depressed. If light therapy helps, continue using it until enough natural sunlight is available, which is typically in the springtime. Discontinuing light therapy too soon may cause the symptoms to return.

When used properly, light therapy has very few side effects. However, some side effects to be aware of may include: eyestrain, headache, fatigue, irritability and inability to sleep (if light therapy is used too late in the day). Individuals who have manic depressive disorders, skin that is sensitive to sunlight, and/or medical conditions that make their eyes vulnerable to sunlight damage should consult a physician prior to starting light therapy.

Tanning beds should not be used to treat SAD, because the light sources in tanning beds are high in ultraviolet (UV) rays, which harm both your eyes and your skin.

Your doctor may also want you to try certain supplements or behavior therapy to treat your SAD if the condition is serious. If light therapy or supplementation alone doesn't work, your doctor may want you to use them together for better results.