A further complication is the fact that some half crazy people seem to know the difference in principal between right and wrong. They seem to have a moral sense that can be appealed to. Maybe no one ever does. I don't know of any books or magazines that are written exclusively for the mentally ill. On the other hand they may hear an exceptional amount of moral philosophy from people they irritate, more than the rest of us do. It's hard to generalize; there are so many kinds of crazy. Some of them are nice people, some of them are jerks.
In my opinion it's a good idea to explain why what they're doing is irritating you, even if the explanation would be painfully obvious to any normal person. It may not do any good but you never know. Like I said, there's all kinds of crazy. Maybe at the bottom of the twisted tunnel in their minds somebody's listening.
WHAT DO YOU THINK?