Have u ever had a model walk into ur studio high as a kite.. and think they were america's next top model? Or just so High u had to throw them out . LOL 

Do alotta models work under the influence ?

yep

i had a model in miami show up with her B/F, (we were shooting in my condo on ocean drive) and the guy asks if he can smoke, so i say do it on the balcony (ok, its 600 sq ft, so i dont really see what he's doing) he comes back in as high as a kite, and i say WTF?! and he said but you said it was cool, i said, i thought you were smoking cigarettes!!

i threw them both out

one picture in my portfolio here was taken while both the model and i were drunk and/or high. can you guess?
and before i offend anyone's professional sensibilities, it was definitely a case of hanging out with a friend and deciding to get the camera out, rather than an appointment/business venture. she's been a friend for years now. relax.

I did a commercial shoot last week with Snoop Dog... as soon as "that" showed up, I made sure my work was done and then left (I am not saying he smoked but I am saying it was present)

Two experiences, one bad, one good:

Quite a few years ago, a model showed up drunk and still drinking.  In the photos, she looked... drunk.  Basically a wasted shoot.  Fortunately, it hasn't happened since then, not quite like that.

About a year ago, I met a model at an outdoor location.  We'd already had a long pre-shoot talk over coffee, and I had a pretty good first impression of her, and knew from her existing work that she was capable of good things.  At the location, she unwrapped a foil packet and asked if I minded if she did some 'shrooms.  Started to  say no... then my intuition said let her make her own decisions.  What followed was one of the best shoots I've ever done, she worked in a non-stop frenzy for three hours, mostly semi-nude, on a 57 degree, damp, windy evening.  We shot til we ran out of light.  Several of those images have graced gallery walls, one is in a permanent collection in Canada, and that particular image... one of the first six taken that day... I count among my most powerful photos in 30 years of doing this.  I'll qualify this by saying she's an exceptional model, one of those rare people who just photographs well no matter what; I doubt most people could get away with what she did.