There is no point treating a depressed person as though she were just feeling sad, saying, 'There now, hang on, you'll get over it.' Sadness is more or less like a head cold- with patience, it passes. Depression is like cancer.
Hope can be a powerful force. Maybe there's no actual magic in it, but when you know what you hope for most and hold it like a light within you, you can make things happen, almost like magic.