I have been thinking about the comments made here about those closest to him not helping him - I too had been thinking the same, but the more I think about it, the more I am thinking that those closest have probably already tried to help him, and failed.
Its well documented how erratic he is. Hes the first to tell us how his undiagnosed Bipolar/ADHD and whatever affects him and we have certainly seen both ends of the spectrum with his moods.
Can we honestly believe that NOBODY has tried to talk to him, to tell him he needs help for those undiagnosed conditions? We only see a snapshot - you can bet your bottom dollar hes much worse off camera.
Now imagine some of those closest trying to tell him he needs help... Do we really believe for one second that "Mr Know It All" will listen? Will he duck. In his world, hes ALWAYS right, and nobody will tell him otherwise, hence his delusions of grandeur.
We have seen his projection and gaslighting tactics. If anyone tells him hes wrong, he turns the situation on them. I can only imagine someone attempting to tell him he needs help or that something hes done is wrong... I can pretty much guarantee he will have given them a million reasons why hes right.
As much I can't stand those around him (for varying reasons) can you imagine actually being around a person like that? It's got to be both mentally and emotionally draining not knowing which face of Dan you are going to get that day. I bet he has them walking on eggshells.
My guess is they will have attempted to intervene at some point but have been fighting a losing battle from the get-go as his ego won't ever believe that someone else could be right, even if it is with his best interests at heart.
I actually would go as far to say that I believe they could still be there out of guilt. Its no secret that all his staff left him - they weren't asked to stand back, that was the excuse he used to cover it up. Hes also been very vocal how those pair are his best mates and left their jobs to join him ( I mean Kaz even left her family behind to help him) so if they said they were gonna leave him, it would hit him hard. How do we know they haven't said about leaving and hes played the "dont leave me, I need you" card?
I notice that not so Cleverley is also now calling Wheeler 'brother' which is particularly worrying as I am told he's a nice guy and we all know what happened to the last bloke that called him 'brother' don't we?
I just think that they are so used to him doing things his way or no way so its been easier to put up and shut up instead of trying to make him see sense.
As the saying goes, you can't help someone who doesn't want to help themselves.
hits the fan
but unfortunately narcissists are so incredibly manipulative and have no conscience. They just rinse, discard and repeat. 
