Seasonal Affective Disorder (SAD) is a type of depression triggered by decreased exposure to daylight, which makes it more common in winter months. Common symptoms include feeling down, having low energy, sleeping a lot, and craving sweet or starchy foods. To help manage SAD, the National Sleep Foundation suggests the following: expose yourself to more daylight by going for a walk outside during the day or buy an artificial light source that mimics sunlight; consume a healthy diet; stay active during the winter months; and seek professional counseling if you have difficulty managing the feelings of SAD.
National Sleep Foundation, November 2017