Subjects who fulfill entry criteria will be randomized to receive ONE of the following 4 treatments in a double-blind fashion: PD 0332334 225 mg BID, PD 0332334 300 mg BID, placebo, and paroxetine 20 mg QAM. PD 0332334 will be titrated up in the PD 0332334 225 mg BID and PD 0332334 300 mg BID treatment groups. The titration of PD 0332334 will be from 125 mg in the beginning of the study. In addition the PD 0332334 225 mg BID and PD 0332334 300 mg BID treatment groups will be titrated down at the end of the study. The 20 mg daily dose of paroxetine used in this study is based on the approved label for the use of paroxetine in patients with GAD. Doses were selected for this Phase 3 study based on safety and efficacy information known about PD 0332334 and pregabalin (PGB), an α2δ ligand approved for the treatment of GAD in Europe