The goals of this within-subject pilot study are: (1) assess the feasibility and safety of
administering the Catechol-O-Methyl-Transferase (COMT) inhibitor, tolcapone, to smokers, and
(2) explore whether tolcapone may reduce abstinence-induced cognitive and affective symptoms
that promote relapse. A secondary exploratory goal is to assess whether these effects may be
more pronounced in smokers who carry a high risk COMT genotype for smoking relapse: COMT
val/val.