Yes he had a history with Demerol and was treated for a dependency to it in 1993.
Was Conrad Murray supplying it to him in 2009? No. Was any of it found in his bedroom after he died? No. Was Demerol in MJ's system when he died? No again.
The actual quote you're referring to starts with the phrase "Over the years.." which is correct because he's referring to past occasions. There is no evidence he was physically addicted to any substance around the time of his death.