Tobacco dependence is known to be the single largest preventable cause of premature death and disability, but little attention is paid to its treatment. It is not just a bad habbit, but a disease, which kills approximately half of smokers.
Although majority of smokers try to quit without help, success rates of these attempts are low (3-5%), but can be largely increased by specialized psychobehavioural treatment (about 10%) and pharmacotherapy: nicotine replacement therapy and bupropion double the chance for quitting (e.g. about 20% of abstinence with intensive intervention) and varenicline triples this chance (about 30%). Fear of potential side effects of the most effective drug, varenicline, seem to be unjustified - several large studies confirmed its cardiovascular and neuropsychiatric safety.
On the other hand - even though small risk of any smoking cessation medication would be confirmed, this one is hugely exceeded by the health risk from smoking.