Usually by speaking to them.
Because there is truth to what they are saying because its their reality.
THANK YOU FOR B.A. :
This is the only way I could Thank you :)
By talking to them calmly and rationally. Note, this is not about trying to convince them of anything. You can still speak with most delusional people.
I was going to make a facetious reply and say in broken English, but on realizing the question was posed in earnest, the answer is a lot more complex, and depends on your ob<x>jective. I don't possess professional therapeutic expertise, but my personal inclination would be to proceed in a manner that did not increase disturbance, and attempt to lead the conversation toward improvement in contact with reality...
Ironically your head went straight to Pharmaceuticals ... huh...
I'm not a psychologist, so I don't know, but I can take a guess that it might be good to try not to "talk them out of it." Maybe you can play along?<br />
I once heard an interview with a woman whose mother was suffering from Alzheimer's, not the same thing, I know, but the woman was living in a delusion that it was 1942 and she was a high school student. She did not recognize her own daughter, but instead was convinced that her daughter was classmate and friend.<br />
At the first the woman was really upset, but it gradually dawned on her that, if she played along with her mom's delusion and just spoke to her as if they really were in high school in the 1940s, she could at least still have some kind of relationship with her mom that way.
Seriously, job for the professionals.
Well that is really good of you. It depends on how they are that day I guess. Knew one woman whose delusions were religious, seeing the Virgin Mary etc. I just listened mainly. Other guy who gets on a bus route quick regularly can get quite aggressive, bit scary, try to calm him down. In general I would say keep them calm and not provoke them. Does this person have any history of violence?
Well yeah do, and well done you.
Enter into their world..lol
Pretend that you're seeing and hearing things that he/she isn't.