Interventions for smoking cessation and reduction in individuals with schizophrenia

Patients with schizophrenia smoke more heavily than the general population and this contributes to their higher morbidity and mortality from smoking-related illnesses. It remains unclear what interventions can help them to quit or reduce smoking.

To evaluate the benefits and harms of different treatments for nicotine dependence in schizophrenia.

We searched the Cochrane Tobacco Addiction Group Specialized Register and electronic databases including MEDLINE, EMBASE and PsycINFO from inception to April 2010.

We included randomized trials for smoking cessation or reduction, comparing any pharmacological or non-pharmacological intervention with placebo or with another therapeutic control in adult smokers with schizophrenia or schizoaffective disorder.

Two reviewers independently assessed the eligibility and quality of trials and 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. Any reported adverse events were noted. Where appropriate, we pooled data using a random effects model.

We included 21 trials (11 trials of smoking cessation; four trials of smoking reduction; one trial for relapse prevention; five trials reported smoking outcomes for interventions aimed at other purposes). Seven trials compared bupropion with placebo; meta-analysis showed that smoking cessation rates after bupropion were significantly higher than placebo at the end of treatment (seven trials, N=340; risk ratio [RR] 2.84; 95% confidence interval [CI] 1.61 to 4.99) and after six months (five trials, N=214, RR 2.78; 95% CI 1.02 to 7.58). Expired carbon monoxide (CO) level and the number of cigarettes smoked daily were significantly lower with bupropion at the end of therapy but not after six months. There were no significant differences in positive, negative and depressive symptoms between bupropion and placebo group. There was no report of major adverse event such as seizures with bupropion.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 are 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.

Bupropion increases smoking abstinence rates in smokers with schizophrenia, without jeopardising their mental state. Bupropion may also reduce the amount these patients smoke. CR may help this group of patients to quit and reduce smoking. We failed to find convincing evidence that other interventions have a beneficial effect on smoking behaviour in schizophrenia.