About two years ago I was cronically depressed, and had many suicidal thoughts. I couldn't find joy in anything at all. I've recovered since then, but I still know what it's like - nothing matters at all, you feel like nobody appreciates you, it's impossible to laugh at anything no matter how funny it is, you just want to go crawl into a hole and die, etc.. Not very fun at all. I have recovered from it, most likely from going to a psychiatrist, at least partially, but I still get into such phases at times...although they aren't as serious as the "original" one.