Varenicline (VAR) is a α4β2 central nicotinic acetylcholine receptor (nAChR) partial agonist. It is believed to mimic the effect of nicotine by stimulating nAChRs and releasing sufficient dopamine in order to reduce craving and withdrawal effects. In the past two years since the approval of VAR there have been some increasing concerns about this medication, particularly in psychiatric smokers. Besides the typical side effects of nausea and insomnia, it has been associated with treatment-emergent suicidality, aggression, psychosis, and induction of hypomania or mania.