yes, opiates are physiologically addicted, and there were no doubt people who abused opiates and were addicted to opiates even back then. but when it is cheap, legal, and widely available, opiate dependence does not cause major social problems.
Alcohol is cheap, legal and widely available here. And it does cause social problems. Every couple of weeks the news are reporting about children starved to death and left alone by their drunk parents, let alone all unreported cases of abuse. While I'm generally against prohibiting anything, I can't say that drugs (including alcohol) do not introduce major social problems.
(I can only speak about Germany, though)
"Little else matters than to write good code." -- Karl Lehenbauer