Dependence on tobacco
Cigarette smoking is a chronic relapsing disease. It is defined as a disorder or disease in the WHO International Statistical Classification of Diseases and Related Health Problems (ICD-10). One of the most important reasons for long-term smoking is physical dependence on nicotine although psychological components, habituation and genetic influences also are involved. Specific nicotine receptors have been identified in the brain and nicotine-dependent rats in which these receptors have been destroyed cease their intake of nicotine. When nicotine binds to these receptors, the neurotransmitter dopamine is released.
Since nicotine dependence plays such an important role in continued smoking, it is not easy to quit and among those attempting to do so, a 1-year quit rate of 10–35% is the rule. Two simple questions can assess whether a smoker is dependent: whether he/she 1) smokes more than 8–10 cigarettes per day and 2) smokes the first cigarette within 30 minutes of waking. It is important to realise that smoking is not simply a lifestyle choice, but a disorder, and that quitting is not just a question of willpower, although motivation is an important factor for success.