Winter depression

More than just the blues, seasonal affective disorder (SAD) affects thousands of Canadians each winter.

Who hasn’t experienced the winter blahs? The short days and long nights are too often accompanied by a sense of restlessness or sadness that can translate into weight gain and a shortage of energy.

Some people, however, experience a more serious form of the winter blues. When depression and fatigue become debilitating, this could signal a condition called seasonal affective disorder (SAD).

Symptoms of SAD include feelings of depression, lethargy, fatigue, cravings for sweets and carbohydrates, headaches, sleep problems, irritability and mood swings.

Seasonal affective disorder, which is thought to be caused by decreased sunlight during the winter months, commonly begins in young adulthood and is thought to be more prevalent in women. In Canada, 2 to 3 per cent of people are affected by the disorder.

Because it is a cyclical condition, the signs of SAD are present only during a particular season. In most cases, the symptoms of SAD appear only during the winter and/or late fall. (A more rare form of the condition is known as reverse SAD, which is characterized by hyperactivity during the summer.)

Many symptoms of SAD are similar to those of major depression. If you regularly experience these symptoms when the seasons change, you may have seasonal affective disorder:

• Sadness or despair

• Anxiety

• Lack of energy

• Withdrawal from friends and family

• Increased sleepiness and irritability

• Loss of interest in work and social activities once enjoyed, including sex

• Increased appetite and craving for foods high in sweets and carbohydrates

• Weight gain

• Difficulty concentrating and processing information

While most people experience “down days,” health experts advise seeing your doctor if you feel depressed or sad for days at a time or if life seems to be losing its pleasure. This is particularly important if your sleep patterns and appetite have changed — and certainly so if you think about death or suicide.

Doctors don’t know the exact cause of seasonal affective disorder, but heredity, age, the body’s chemical makeup as well as the availability of sunlight may all play a role.

Researchers believe the condition may be related to the body’s internal clock. Reduced sunlight may disrupt the circadian rhythms that regulate your body’s temperature and hormone production. And in turn, this disruption may cause depression.

Moreover, some scientists theorize that melatonin, a sleep-related hormone that’s also linked to depression, might be the culprit. Production of melatonin increases during long winter nights.

Other studies suggest that lack of serotonin, a brain chemical that regulates mood and behaviour, seems to be triggered by sunlight. People who are depressed are known to have decreased levels of serotonin.

While there is no cure for SAD, like depression, it often can be successfully managed. Treatments may include:

Light therapy
This is the main treatment for many people with seasonal affective disorder. It consists of daily exposure to bright light (10 to 20 times brighter than ordinary indoor lighting) to help balance brain chemicals and reset body rhythms. Used to simulate sunlight, the treatment usually consists of sitting in front of a high-intensity fluorescent light source for thirty minutes or more each day. This can be done simultaneously with other activities such as reading or eating breakfast.