I've smoked opium a handful of times. It smells wonderfully.
And yet, if I take any drug regularly, I'm using something with THC in it (hash or pot, in general). I currently do not, however, and tend to have a few drinks and get high on the weekends. Not a big deal if I don't, though.
I've had medical grade heroin in the hospital (morphine didn't take care of the pain). No withdrawal, though I was wonderfully high. Haven't gone to a morphine habit.
The prudent thing to do is not to say, "opioids are instantly addictive", but to give folks safe ways to detox from them and give folks information on signs of addiction - because not everyone has such experiences.