Following the initial telephone screening, eligible participants will be scheduled for a screening evaluation session.
Following the screening evaluation, participants who pass the medical screening and meet all other inclusion criteria will be scheduled for their first assessment and then randomized to receive standard varenicline (SV), extended varenicline (EV), or extended varenicline plus facilitated extinction (EV + FE). The randomization list will be generated by the study statistician. It will be stratified by gender and will employ a variable block randomization that will guarantee that the arms are balanced when a given block is filled.