The study's major aim is to investigate the ability of a commercial Electronic Nicotine Delivery Device (E-Cigarette) to induce long-term smoking reduction/abstinence in smokers unwilling to quit. Secondary aims are to investigate changes in withdrawal symptoms and cravings and to examine whether concomitant use of the E-Cigarette and smoking is safe. The study will monitor smoking reduction/abstinence effects, changes in withdrawal symptoms, and adverse events of a currently marketed device in Italy ("Categoria" electronic cigarette - "NO nicotine" cartridges). The primary hypothesis is that the E-Cigarette is a safe device that allows smoking reduction or abstinence in smokers possibly by suppressing withdrawal symptoms and cravings independently from nicotine delivery.

The electronic cigarette (E-Cigarette) is an electronic nicotine delivery systems designed for the purpose of nicotine delivery to the respiratory system where nor tobacco nor combustion are necessary for its operation. For these reasons, it is possible that this product may be safer than cigarettes. Marketing claims also include that they can be useful smoking cessation aids. Although E-Cigarette may produce lung delivery of nicotine similar to that of tobacco cigarettes and reproduces the gesture component associated with tobacco smoking, very little is known about the effect of E-Cigarette on the smoking habits of regular tobacco smokers. Therefore, we designed a prospective observational study consisting of 8 office-based visits (a baseline visit and a 2, 4, 6, 8, 10, and 12-weeks and a final visit at 24-weeks) to monitor possible modifications in the smoking habits of a group of well characterized regular smokers experimenting the e-cigarette focusing on long-term smoking reduction/abstinence, changes in withdrawal symptoms/cravings and adverse events. Specifically, 100 smokers will be given "Categoria" electronic cigarette loaded without nicotine ("NO nicotine" cartridges) and followed up for a total of 24 weeks.\

Inclusion Criteria:

• healthy smokers unwilling to quit, between 18 and 60 years of age. They should report a cigarette intake of ≥ 15 cig/day for at least 5 years. At screening they must provide a CO level of ≥ 15 ppm and an FTND ≥ 5.

Exclusion Criteria:

• alcohol and illicit drug use, breastfeeding, or pregnancy. Individuals who report current attempts to quit smoking and previous experience with electronic cigarettes will be also excluded.

Regular smokers from Catania in Italy recruited following the placement of an advertisement in a local newspaper.