Is smoking "just a habit" or are you addicted? Take this test and find out your level of dependence on nicotine.
Heatherton TF, Kozlowski LT, Frecker RC, Fagerstrom KO. The Fagerstrom Test for Nictoine Dependence: A revision of the Fagerstrom Tolerance Questionnaire. British Journal of Addictions 1991;86:1119-27.