During late fall and winter, the days get much shorter, grayer and definitely colder. It's almost enough to make you want to stay in bed forever. This may be a common thought for many of us but for some, the winter months can bring on a serious depressive state. People with SAD experience depressive symptoms in the fall and winter that usually remit in the spring or summer. About 70 to 80 percent of SAD patients are women who usually develop the disorder in their 30s.
Location also seems to play a part in the disorders.
The further north a person lives, the more likely they are to develop SAD, since it is related to the amount of daylight. Symptoms of SAD are atypical of most major depressive disorders, which are usually characterized by loss of appetite, difficulty sleeping, loss of motivation and a depressed mood. In contrast, SAD symptoms include increased sleep and difficulty waking, increased appetite and carbohydrate cravings, weight gain, and general sluggishness. SAD can be treated with antidepressant drugs, especially those that increase levels of serotonin in the brain. There is also good evidence that phototherapy works to treat SAD, but it has to be the right kind of light, St. John noted.