Seasonal affective disorder (SAD) affects many people during the winter months. For these individuals, the shortened, dark days of winter spell months of gloom often accompanied by decreased mood and energy, and a craving for carbohydrate foods. In the United States, travel to a sunny climate during winter has long been credited with making people feel much better.
Researchers around the world are examining the role of daylight and its effects on the body. Light causes changing levels of two chemicals in our bodies -- serotonin and melatonin.
Serotonin is a chemical in the brain. Serotonin levels are lowest during the winter months. Some antidepressant medications can be used to increase serotonin levels.
Melatonin is a hormone secreted by the pineal gland, which is in the brain. Melatonin has a strong daily rhythm, as it is released only at night. The pineal gland's production of melatonin stops when daylight reaches the eye.
The concept of light as therapy for seasonal affective disorder has proven to be quite popular. The idea of mood, appetite and behavior being related to seasonal patterns also is well received. However, the benefits of "light therapy" are still being researched. There remain many interesting but unanswered questions. Therapy, diet, exercise and medication remain the interventions most widely recognized for SAD.
Anyone experiencing a persistent or recurrent mood disorder is encouraged to seek professional guidance. If you or someone you know appears to suffer from winter blues, call for help.