Safety and effectiveness of varenicline in a veteran population with a high prevalence of mental illness.

Background: Varenicline is a selective nicotinic receptor partial agonist used to aid in the process of smoking cessation. Research on varenicline's approval for marketing demonstrated that after 12 weeks of treatment, at least 44% of patients successfully quit smoking and, on average, 13% of individuals discontinued therapy due to an adverse drug event (ADE). Growing postmarketing data linked varenicline to an increase in neuropsychiatric symptoms.