What's sad is that Ted did try to drag him down. Unintentionally... I mean, I don't believe he wanted to, it just happened.
I'm SO, SO glad Emmett didn't get addicted to that stuff along with Ted. He could have easily developed one, but fortunately he didn't. His resolve wasn't very strong, though, and it took Brian basically telling him "Ted's going to drop dead soon if he continues down this path" before he could get out of that situation.
Brian just might have saved both their lives here, because had Emmett gotten hooked on that stuff, they would have been each other's undoing.