Addiction is defined as repeated use of a psychoactive substance or substances, to the extent. Nicotine addiction is the fundamental reason that individuals persist in using tobacco products, and this persistent tobacco use contributes to many diseases. Smoking is primarily practiced as a route of administration for nicotine through the lungs; it is a way of getting nicotine into your system rapidly. Some people use hand-rolled loose tobacco, while others smoke pipes, cigars or hookahs, mainly industrially manufactured ones. Dopamine is a neurotransmitter that is released when nicotine enters the body, and is the chemical that makes you feel calm and relaxed.
The gum and lozenge come in 4 mg and 2 mg doses, while the inhaler and tablet come in the 2 mg dose only. Sets of patches come in three sizes: the 24-hour patch has dosages of 21 mg, 14 mg and 7 mg, and the 16-hour patch has dosages of 15 mg, 10 mg and 5 mg. Of the daily smokers, 55.6% (95% CI 51.3–59.9) had made quit attempts and 36.2% (95% CI 32.1–40.4) had used nicotine replacement therapy (NRT). In all, 34.1% (95% CI 25.2–44.3) of all occasional smokers reported having intended to quit but they had seldom made more than one attempt whereas 20.2% of daily smokers had made at least three attempts. Recommendations are to prohibit tobacco-product advertising and to require stronger health warnings labels.