Ideally it's a social club. I didn't plan on joining a fraternity in college, but I was invited to join by friend who were in one. It's a specifically anti hazing organization and has a leadership education program that we all did that probably would have been really useful if I wasn't a shit head college student. I still play D&D with friends I made there who I may not have met otherwise.
Like any social club the culture comes from the members, if you have a bunch of exclusionary bullies then that's what you get, and that's all too common.
He has a "freakishly large neck" (his words) that prevents him from getting enough oxygen when he sleeps.
When he was young he spent hours under a house with insecticide spray in the air.
I'm sure there are other tidbits in forgetting, but suffice it to say that you're underselling him by saying he has "a" yet to be defined mental disorder.
You gotta try the Proin Ultrices