[MWF]

Ok, this is just an add-on, but I'm really starting to think my best friend has some sort of delusional disorder or something. He's always done this, but he just keeps saying demonstrably false things about himself to make himself feel good (delusions of grandeur). I've only recently caught on to how detached from reality he is because he's been living with me for so long. He's not schizophrenic or anything, but theres just a long pattern of him saying completely nonsensical things about himself that he SHOULD know that I know are false and have nothing to do with reality. And now that I remember, his wife used to just see things and wander off. That was only a few years back. I think she's had it dealt with, though, because I haven't heard of anything like it since.
I'm getting genuinely worried. Is there anything I can or should do about this? Thing is, there's no advice that he would follow, even if we had some sort of family intervention for him.

Edit: I looked it up, and he appears to have a ton of symptoms for delusional disorder.