Ever feel kind of blue in the depths of winter when there’s no sun and the temperatures dip below freezing? It turns out, that’s not just a mood. There is a medical term for the winter blues and it affects an estimated 10 million Americans each year. Seasonal Affective Disorder or SAD is a type of depression that manifests during a specific season year after year. While there are people who experience SAD in the summer, the majority of cases occur in the winter months.