not neccessarily. though the drugs are similar, even the same drug given differently (ie different site, at different rate) will induce a different response in the subject, particularly the psych drugs
My ex in college shot that shit about 3-4 times a day in our 2nd semester. I used to have to drive her porsche into the shittiest neighborhood in Philly to cop that shit with her b/c you can't let a blonde haired blued little rich girl into a place like that alone.
I have howver, gotten a 15mg injection of morphine when I was in the hospital for a collapsed lung. It was beautiful.
Snorting morphine was pretty cool actually. The hallucinations were interesting, but I pretty much only got them when I closed my eyes and relaxed, or while sleeping. Morphine is pretty good. OC's are easy though and make you feel pretty good as is - unless you take too much which is unpleasant.
I think drugs in general are WAY less addictive than people think they are. They certainly are in terms of physical addiction. But mental is a whole other matter.
Agreed for some. But I think those people are in the minority of drug users in general. I think for most people use them, they never interfere with their day to day lives.