Maintenance pharmacotherapy normalizes the relapse curve in recently abstinent tobacco smokers with schizophrenia and bipolar disorder

OBJECTIVE To compare the effect of maintenance pharmacotherapy on sustained abstinence rates between recently abstinent smokers with schizophrenia and bipolar disorder (SBD) and general population smokers without psychiatric illness. METHOD We performed a person-level, pooled analysis of two randomized controlled trials of maintenance varenicline, conducted in adult smokers with SBD and general population smokers, controlling for severity of dependence. Smokers abstinent after 12-weeks of open varenicline treatment were randomly assigned to ≥12-weeks maintenance varenicline or identical placebo. RESULTS In those assigned to maintenance placebo, the abstinence rate at week-24 was lower in those with SBD than for those without psychiatric illness (29.4±1.1% vs. 61.8±0.4%, OR:0.26, 95% CI: 0.13, 0.52, p<0.001). In smokers assigned to maintenance pharmacotherapy, however, there was no effect of diagnosis on abstinence rates at week-24 (87.2±0.8% vs. 81.9±0.2%, OR: 1.68, 95% CI: 0.53, 5.32, p=0.38). Time to first lapse was shortest in those with SBD assigned to maintenance placebo (Q1=12days, 95%CI: 4, 16), longer in those without psychiatric illness assigned to maintenance placebo (Q1=17days, 95%CI: 17, 29), still longer in general-population smokers assigned to maintenance varenicline (Q1=88, 95% CI:58,91, and longest in those with SBD who received maintenance varenicline (Q1>95days, 95%CI:non-est), (Χ23df=96.99, p<0.0001; all pairwise comparisons p<0.001). CONCLUSIONS Following a standard 12-week course of pharmacotherapy, people with schizophrenia and bipolar disorder were more likely to relapse to smoking without maintenance varenicline treatment. Maintenance pharmacotherapy could improve longer-term tobacco abstinence rates and reduce known smoking-related health disparities in those with SMI.