Reference Interventions Study characteristics Duration Outcome Int. J. Environ. Res. Public Health 2012, 9 1. Tobacco smoking cessation reviews Cahill and Ussher 2007 [13] Gourlay et al. 2004 [14] Hughes et al. 2007 [16] Rimonabant (cannabinoid receptor antagonists) and placebo for tobacco cessation Clonidine and placebo for tobacco cessation Antidepressants and placebo for smoking cessation Table 1. Details of included reviews. RCTs in adult smokers Lost to follow up regarded as continuing smokers Prolonged abstinence defined biochemically at each study visit RCTs in adult smokers Control (placebo) usually involved some form of behavioural therapy. RCTs in adult smokers Control (placbeo) sometimes used behavioural therapy or similar interventions At least 6 months 4.5 months to 1 year At least 6 months from start of intervention Smoking status at minimum of 1 year Smoking status by a variety of methods, including self report Abstinence from smoking, assessed at follow up by various means Abstinence with Intervention Placebo Prolonged abstinence Prolonged R 20 mg week 50: abstinence week 87/528 (16.4%) 50: 57/521 (11%) Prolonged abstinence R 5 mg week 50: 63/518 (11%) Smoking cessation at longest time: 98/393 (25%) Smoking cessation at longest time: 55/383 (14.4%) Nortriptyline Smoking cessation at 6 months or longer: 100/480 (20.8%) Bupropion Smoking cessation at 6 months or longer: 1,056/5,557 (19%) Placebo Smoking cessation at 6 months or longer: 49/495 (9.9%) Bupropion Smoking cessation at 6 months or longer: 417/4383 (9.5%) Comments RR 1.5 (1.1 to 2.1) for 20 mg RR 1.6 (1.2 to 2.2) RR 2.0 (1.5 to 2.8) RR 1.8 (1.6 to 1.9) (data here for clinical setting, 6 and 12 months follow up, type of patient) 196