Some catastrophic moments invite clarity, explode in split moments: You smash your hand through a windowpane and then there is blood and shattered glass stained with red all over the place; you fall out a window and break some bones and scrape some skin. Stitches and casts and bandages and antiseptic solve and salve the wounds. But depression is not a sudden disaster. It is more like a cancer: At first its tumorous mass is not even noticeable to the careful eye, and then one day -- wham! -- there is a huge, deadly seven-pound lump lodged in your brain or your stomach or your shoulder blade, and this thing that your own body has produced is ac