Two people died by suicide (both in the varenicline arms) and four attempted to do so (two in the varenicline arm and two in the placebo arm). Table 4 summarises the Peto odds ratios, risk differences, and 95% confidence interval for the primary and secondary outcomes. Because of the small numbers of events, we combined suicide and attempted suicide into a single outcome. Thirty one trials reported suicide and suicide attempt; the Peto odds ratio for varenicline versus placebo was 1.67 (95% confidence interval 0.33 to 8.57; P=0.54, I2=10.3%) and the risk difference was 0.0003 (−0.002 to 0.003; P=0.81, I2=0.0%). Twenty trials reported suicidal ideation (figs 2 and 3); the Peto odds ratio was 0.58 (0.28 to 1.20; P=0.14, I2=0.0%) and the risk difference was −0.003 (−0.009 to 0.002; P=0.24, I2=0.0%). Thirty one trials reported on depression (figs 4 and 5); the Peto odds ratio was 0.96 (0.75 to 1.22; P=0.74, I2=0.0%) and the risk difference was −0.001 (−0.01 to 0.01; P=0.74, I2=0.0%). Death was reported in 36 trials (total 13/5760 in the varenicline group and 11/4887 in the placebo
