Modulating tobacco smoking rates by dopaminergic stimulation and blockade.

This study was designed to demonstrate that dopaminergic stimulation would result in decreased smoking behavior and nicotine intake, whereas dopaminergic blockade would result in increased smoking behavior and nicotine intake, in the same subjects. In prior human studies, a dopaminergic antagonist, haloperidol, increased smoking and/or nicotine intake, and a dopamine agonist, bromocriptine, decreased smoking. The smoking behavior of 20 heavy smokers was observed on two separate visits in a randomized, double-blind, repeated-measures-within-subject design.