Many parts of the country experience a significant reduction in the amount of sunlight generated during the winter months. Lack of exposure to the sun's rays can affect each person differently. Sometimes the lack of sunlight during winter can result in the development of Seasonal Affective Disorder (SAD).
SAD is a type of depression that can leave those affected feeling moody and sadder than usual. While there are still many things the medical community needs to learn about treating SAD, light exposure therapy does seem to be a viable treatment option.