Nicotine has just about everything going for it in the addiction department.

First of all, it’s legal, and even though it is becoming inconvenient to smoke, you can still have a smoke pretty much when you need one.

Second, and very much related to our first reason, are two factors:

Nicotine enters our bloodstream within seconds, giving us an immediate lift, and it doesn’t stay in the blood for very long, only for a few minutes.  We then need to smoke again to get the “lift” back.  Thus, we have two powerful reinforcing effects: immediate reward, and easily repeatable reward. Cigarettes and nicotine are extremely easy to manipulate to get the desired results.

Added to that is the fact that the results are consistent.  Although we do become accustomed to nicotine so that it has somewhat less of an effect, it continues to give us some reward whenever we ask it to.

Nicotine is one of the most highly-addictive substances known, and because we are able to use it just about any time we like, it creates profound changes in our brain: physical changes that in a very short time cause us to need the stimulation of nicotine in order to function normally.  Furthermore, even though we may stop smoking, until the physical changes have reversed we continue to desire nicotine.  This can take a very long time, and the reversal can itself be reversed by exposure to only small amounts of nicotine, which can recreate the craving.

There is also a lot of habit associated with smoking, in addition to the physical addiction: lighting up after a meal, with a cup of coffee, after sex, while on the phone, driving in the car, during a break from work.  We develop physical habits, too: holding and gesturing with a cigarette or cigar, lighting up to cover uncomfortable social moments, to occupy our hands when bored, and so forth.  These physical habits, which must themselves be broken, only add to the difficulty of quitting.  This writer remembers quite clearly the day he had a disagreement with his wife and found himself reaching to his breast pocket for a cigarette — more than 10 years after he successfully quit smoking.

It is easy to see why it’s harder to get over cigarettes than heroin.  An addict knows that heroin is ruining his life, and that the next fix might kill him, or lead him back to a life where he might as well be dead.  Smokers, on the other hand, know intellectually that they are ruining their health, but they also know that the next cigarette isn’t going to be the one that kills them.  It is easy to say “later…I’ll quit after (insert excuse for smoking here).”  Equally, it’s easy to relapse, thinking “I’ll just buy one pack.”

Been there.  Done that.  Burned holes in lots of T-shirts.

These are the reasons that it is so difficult to quit, and why it is so easy to get hooked to begin with.  About 3% of people who attempt to quit cold turkey manage to do so.  The success rates for nicotine replacement vary from 10 to about 20%, and prescription meds (which can create their own side effects) hover around 25 – 30%.  Quitting ain’t for sissies.