Here’s a list ranking the addictiveness potential of various drugs:
Ice, Glass (Methamphetamine smoked) 99
Crystal Meth (Methamphetamine injected) 93
Valium (Diazepam) 85
Quaalude (Methaqualone) 83
Seconal (Secobarbital) 82
Crank (Amphetamine taken nasally) 78
PCP (Phencyclidine) 57
Ecstasy (MDMA) 20
Psilocybin Mushrooms 18
[Research by John Hastings]
I believe these are ranked according to former users’ opinions on which drugs are easiest to become addicted to, and which ones are hardest to quit.
IMO, with what exposure I’ve had to these substances (I’ve used, or at least tried, nine of them), this list seems pretty accurate to me.
I’m a smoker, and some years ago when I first heard that nicotine was the most addictive drug, I thought that was a laughable statement, certainly when compared to the addictiveness of, say, heroin. Now, I tend to believe that it’s quite probably true. I have no experience with heroin, but I do understand it can have severe withdrawal symptoms. I would imagine the exhaustion of the extreme highs and lows of heroin give pretty strong encouragement to a user to quit it. Nicotine seems to be more subtle; no extreme highs and lows, it just sucks you further and further into addiction, but doesn’t directly destroy your day to day life. It doesn’t give you the motivation to quit that heroin does, possibly making it even harder to quit.
This is all MHO, of course, but my vote would be for nicotine.