SAD is type of depression that most often affects people in the fall and winter months. SAD is likely caused by the body's reaction to decreased daylight hours. Signs return at the same time each year and last until spring.

The signs of SAD are likes those of depression. You may:

• Feel tired all of the time or lack energy
• Sleep too much
• Eat more, especially sweets and comfort foods leading to weight gain
• Have problems with concentration
• Lose interest in things that you enjoy
• Feel hopeless, guilty, worthless, helpless or irritable

If you have any of these signs for more than 2 weeks or you are thinking of harming yourself or others, see your doctor.

Talk to your doctor about your signs. If your signs are mild, your doctor may suggest that you increase your exposure to sunlight by spending time sitting next to a window or taking a walk each day. If your signs are more severe, light therapy is often used. Light therapy uses a special light box to expose you to bright light. You sit in front of the light box for 30 to 90 minutes each day often in the morning. Tanning booths should not be used to treat SAD since the light rays are high in ultraviolet (UV) rays that harm your eyes and skin. Medicines and therapy may also be used to treat SAD.