Feeling sad? It could be SAD – Seasonal Affective Disorder – a mood disorder that creeps up on long, dark days. Yes, the winter blues are a real disorder. And it affects millions of people each year. But rather than dwell in the darkness, try these 5 winning ways to ward off seasonal depression. 1.Let In The Light While it might be too cold and miserable to venture outside, we still need a good dose of vitamin D from the sun to boost our mood. Research suggests a vitamin D deficiency is linked to depression. So on dark days, simply sit near natural light. It could be under a skylight or near a window.