We searched electronic databases including MEDLINE, EMBASE and PsycINFO from inception to October 2012, and the Cochrane Tobacco Addiction Group Specialized Register in November 2012.
SELECTION CRITERIA: Two reviewers independently assessed the eligibility and quality of trials, as well as extracted data. Outcome measures included smoking abstinence, reduction in the amount smoked and any change in mental state. We extracted abstinence and reduction data at the end of treatment and at least six months after the intervention. We used the most rigorous definition of abstinence or reduction and biochemically validated data where available. We noted any reported adverse events. Where appropriate, we pooled data using a random-effects model.
MAIN RESULTS: We included 34 trials (16 trials of cessation; nine trials of reduction; one trial of
relapse prevention; eight trials that reported smoking outcomes for interventions aimed at other purposes). Seven trials compared
bupropion with placebo; meta-analysis showed that cessation rates after
bupropion were significantly higher than placebo at the end of treatment (seven trials, N = 340; risk ratio [RR] 3.03; 95% confidence interval [CI] 1.69 to 5.42) and after six months (five trials, N = 214, RR 2.78; 95% CI 1.02 to 7.58). There were no significant differences in positive, negative and depressive symptoms between
bupropion and placebo groups. There were no reports of major adverse events such as
seizures with
bupropion.Smoking cessation rates after
varenicline were significantly higher than placebo, at the end of treatment (2 trials, N = 137; RR 4.74, 95% CI 1.34 to 16.71). Only one trial reported follow-up at six months and the CIs were too wide to provide evidence of a sustained effect (one trial, N = 128, RR 5.06, 95% CI 0.67 to 38.24). There were no significant differences in psychiatric symptoms between the
varenicline and placebo groups. Nevertheless, there were reports of suicidal ideation and behaviours from two people on
varenicline.Two studies reported that contingent reinforcement (CR) with money may increase smoking abstinence rates and reduce the level of smoking in patients with
schizophrenia. However, it is uncertain whether these benefits can be maintained in the longer term. There was no evidence of benefit for the few trials of other pharmacological
therapies (including
nicotine replacement therapy (NRT)) and psychosocial interventions in helping smokers with
schizophrenia to quit or reduce smoking.
AUTHORS' CONCLUSIONS:
Bupropion increases smoking abstinence rates in smokers with
schizophrenia, without jeopardizing their mental state.
Varenicline may also improve smoking cessation rates in
schizophrenia, but its possible psychiatric adverse effects cannot be ruled out. CR may help this group of patients to quit and reduce smoking in the short term. We failed to find convincing evidence that other interventions have a beneficial effect on smoking in
schizophrenia.