Winter & Depression

Depression, which is sometimes called major depressive disorder or unipolar disorder, is a mental illness characterized by feeling blue or sad for prolonged periods. Often depression starts in the wintertime. This type of depression is called seasonal affective disorder, or SAD. There are a couple of treatment possibilities for this common type of depression.

Symptoms of Depression

• Depression is marked by sad feelings that last for at least two weeks. It can also cause other emotional symptoms such as irritability, feelings of worthlessness or hopelessness, and excessive feelings of guilt. Often people with depression feel fatigue and don't take pleasure in activities they used to enjoy. Depression can also manifest itself physically, often as a lack of or increased appetite and weight gain or loss. It can affect sleep, causing insomnia or excessive sleeping. Depression can even have cognitive symptoms, such as difficulty concentrating or making decisions.

Seasonal Affective Disorder

• Seasonal affective disorder is a type of depression that sets in or starts in the winter months. Unlike other types of depression, it may improve as spring comes on. It is often a cyclical, recurring disorder--you'll feel depression every winter and begin to feel better each spring.

Causes

• A study by Alfred Lewy at the Oregon Health and Science University found that most of the symptoms of seasonal affective disorder are caused by body rhythms that are not in sync with the sun. Often the body gets out of sync with the sun because of winter's shortened days. The pineal gland, which regulates body rhythms, secretes a hormone called melatonin during the night. This can affect your sleep wake cycle and other rhythms. When it gets dark too early in the day, the pineal gland and the body's sleep wake cycle get out of sync.

Treatment

• Light therapy is the most common treatment for seasonal affective disorder. In light therapy you're exposed to an artificial light that mimics sunlight. Light therapy often takes place in the early morning, before the sun has risen, simulating an earlier sunrise. A study that looked at the results of several other studies and was published in the American Journal of Psychiatry showed that light therapy was very effective at treating the symptoms of seasonal affective disorder but less helpful in treating other types of depression. SAD that does not respond to light therapy is often treated with antidepressant medications and psychotherapy, both of which are used for all forms of depression.

Prevalence

• Seasonal affective disorder is far more common in northern climates, where days can be very short in winter. A study done at the University of Alaska in Anchorage found that more than 9 percent of the people studied, all of whom lived in Fairbanks, Alaska, suffered from SAD. SAD affects more women than men and is likelier to occur in people under age 40 than those older than that.