I have a friend suffering from agorophobia. This obviously combines depression aswell, but occasionally they will slip very quickly into quite severe depression. It can come on within a matter of minutes and they can feel it coming. They then enter a very dark place, which can last for weeks. After a day of this depression they will have lumps on the head as if they have been hit with something, making the head very tender. Are these lumps a normal side effect of depression or do they suggest something more physical than mental? Something that can actually be tested and measured? If so, what might this be?