Delusions

Can anyone tell me about delusions? This seems to my son's biggest issue right now. What's it like? What works best? How do I talk to him about it? Why if he's having these, does he do so well in school? He is in a RTC right now and is very very quiet is that because of the delusions? He feels that he is doing okay until somebody else does something that bothers him and then he can't "get back there." I am trying to better understand him and what this must be like. Can he learn to recognize them and stop them? Please if you have experienced them, can you share with me and what helps you to cope? He is just 17 and had his break in May 08.

Thanks,

Kathy