I never heard Pitt smoked cigarettes.

Ex-wives and ex-girlfriends say he smoked a ton of pot.
When I was in grad school, I worked in the gossip business.
The studios hire a personal trainer to get the actors into the shape they wanted them to be in for the role. The connected personal trainer gets the stuff and the studio foots the bill.
It was like when Al Davis would buy al the steroids for his players.
He would just lay it all out on a big table in the locker room and told the players to take what they wanted.
When asked, he said he'd rather buy quality stuff for his players rather than having them get crap off the street.