Another meta-analysis examined the long term efficacy and safety of varenicline in trials with a minimum follow-up period of 12 months.70 A meta-analysis of the main psychiatric related adverse effects (which combined depressed mood, other mood disorders, bipolar disorder, delirium, suicidal and self injurious behaviours, adjustment disorders, and abnormal thinking into a single outcome) did not show a “significant increase of psychiatric side effects for varenicline compared with placebo.”70 This meta-analysis, however, included only three trials, and the combined psychiatric outcome was non-specific. The authors reported an increased risk of insomnia (relative risk 1.65, 95% confidence interval 1.29 to 2.11), abnormal dreams (2.78, 2.07 to 3.73), and sleep disturbance (2.09, 1.62 to 2.69) but no increased risk of irritability (1.14, 0.75 to 1.73), which is consistent with our findings.70
