What is the hardest to quit- alcohol, cocaine, or tobacco?

It depends. On what you are most addicted to. Most addicts find that they have a "drug of choice", and that is the one that is the hardest to quit.

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What is the hardest to quit- alcohol, food, or cigarettes (tobacco)?

Pick your poison. All are addictive and usually have physical addictions as well a psychological components. There is no way to score one higher than another. Just pick one and start from there. Talk to your family doctor. Read more...