Here’s a list ranking the addictiveness potential of various drugs:
Nicotine 100
Ice, Glass (Methamphetamine smoked) 99
Crack 98
Crystal Meth (Methamphetamine injected) 93
Valium (Diazepam) 85
Quaalude (Methaqualone) 83
Seconal (Secobarbital) 82
Alcohol 81
Heroin 80
Crank (Amphetamine taken nasally) 78
Cocaine 72
Caffeine 68
PCP (Phencyclidine) 57
Marijuana 21
Ecstasy (MDMA) 20
Psilocybin Mushrooms 18
LSD 18
Mescaline 18
[Research by John Hastings]
from
http://www.totse.com/en/drugs/miscellaneous_drug_information/addictio.html
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.