As the days grow shorter and the sun slips away a little earlier each evening, many of us start to feel a change — not just in the weather, but in ourselves. For some, fall brings cozy sweaters and comfort. For others, it can bring a quiet heaviness that’s hard to explain. This time of year, I often hear people describe feeling more tired, unmotivated, or withdrawn. If this sounds familiar, you’re not alone — it may be something called  Seasonal Affective Disorder , or  SAD .