Addictions to any substance have a number of common features, but each specific compound add its own vile flavour to the experience.
Nicotine is particularly malevolent as the need for a cigarette simply serves to ease that state of disquiet which is nicotine withdrawal and the relief of this and the subsequent 'restoration' to a functional state is the pleasurable aspect.It adds little to the baseline normal state.
Opiates on the other hand will 'normalise' the withdrawing user plus add more-but the longer one is habituated, this 'more' diminshes with time to a state of emotional and physical numbness.
Its true an addict can simply choose to stop their use, but choosing is a psychological decision which is worth little unless its followed through with action.The required action will not take place without a degree of soul-searching and a realisation that the last person you want to be bull-shitting is yourself.
Spending too much time analysing why the addict has got themself into this state is not fruitful for many addicts as the reason for addiction tends to be quite straight-forward.You take a substance which imparts some pleasure, you like it, the pleasure you receive is here and now whilst the future seems an abstract concept and the consequences of your actions today dont seem as relevant to your tomorrows as they should be and you blunder on into a mire thats deeper than you could have imagined.Clearly, this does not apply to all but I suspect it explains the situation in many cases.
In Wordsworths 'The Prelude' there is a bit where some walkers are crossing the alps, aiming to get to the highest point.They meet some travellers coming from the other direction and ask them how far the summit is.They are told they have already passed it.I find this an excellent metaphor for the process of getting addicted.
For me personally, the process of reversing an opiate habit without attempting a short-cut to a cure was the only way to ensure I feared and respected these compounds subsequently.The pain of the process fades with time but I do recall that it almost defeated me.The experience has had many benefits-not least of which is being able to live a life free of servitude to a chemical.It has also made me much more forgiving of others faults and weaknesses, less frivolous and much more humble.But this is just my experience.
I am paranoid of my brain. It thinks all the time, even when I'm asleep. My thoughts assail me. Murderous lechers they are. Thought is the assassin of thought. Like a man stabbing himself with one hand while the other hand tries to stop the blade. Like an explosion that destroys the detonator. I am paranoid of my brain. It makes me unsettled and ill at ease. Makes me chase my tail, freezes my eyes and shuts me down. Watches me. Eats my head. It destroys me.