Yes, Miles. I did not wish to go into exhaustive detail in my reply to this fairly straightforward Quora question. But you are completely correct.
There has been substantial evidence that, in addition to nicotine, cigarette-smoke contains MAOIs which prevent the breakdown of dopamine, serotonin and norepinephrine etc.
Nicotine, in and of itself, does not appear to do this to any great extent.
It seems to me to be probable (although this has not yet been definitively confirmed) that true ‘addicts’ (amongst whose number I count myself) are born with a genetically mediated malfunction in the production, metabolising and reuptake of some or all of these neurotransmitters.
This results in a mood-disorder (addictive disease) which we attempt to self-medicate with a variety of different mood-altering substances and processes: drugs, both legal and illegal, prescribed or acquired by less orthodox means, compulsive overeating, compulsive undereating, compulsive overspending, compulsive gambling, compulsive sexual activities, compulsive helping, compulsive controlling, compulsive risk-taking etc., etc., etc.
Inevitably, with the development of tolerance, upregulation and downregulation of different receptors, each of these substances and processes ceases to have the desired effect – leading to even greater indulgence and/or cross-addiction. Many ex-smokers, for instance turn initially to compulsive overeating and become grossly overweight.
But I think that the general thrust of both your answer and of mine is that (short of emphatically and intentionally confrontative professional intervention) there is not much that anyone can do or say to a person who is in active addiction that will provide sufficient impetus and motivation to initiate the lengthy and profound changes required for recovery.
Addictive disease, unfortunately, does not distinguish between medicinal products (e.g. varenicline, buprenorphine etc.) and non-medicinal products or alkaloids. Nor does it distinguish between those that are legal and those that are illegal. As long as they are mood-altering in some way, they will do just fine.
I sometimes think that if you were to put a true-born addict on a barren desert island, he would find an addictive use for sand.