"I think the fall is getting to me." That's what a friend told me on the phone recently. "You're middle-aged now, and suddenly you're getting the autumn blues?" I said jokingly. He laughed awkwardly, then began telling me about his life lately. Seeing the darkening sky on his way home from work drains his energy. Once home, he lies on the couch and does nothing. Even after sleeping in on weekends, he doesn't feel refreshed. And after dinner, he finds himself reaching for bread and snacks. As I listened, I began to wonder whether it was really something that could simply be blamed on the season. In Korea, the expression "gaeul tada," literally "to be affected by autumn," carries a certain romanticism. It describes that wistful feeling that arrives with falling leaves, when even a familiar song can unexpectedly stir the emotions. But persistent sadness and lethargy, along with losing interest in hobbies once enjoyed, are a long way from romantic autumn melancholy. According to the U.S. National Institute of Mental Health, seasonal affective disorder (SAD) is a "type of depression characterize