Was Edgar Allen Poe addicted to opiates?

I've heard this before, but I'm not sure if this is rumor. I'm sure he's used his fair share of opiates, since he talks about the use of opiates in many of his short stories. But was he truly addicted? I've also heard that opiates were somewhat of a catalyst for his creativeness, in the same way alcohol has been a catalyst for many great writers. Many great authors have been abusers of some kind. What do you think?