Efficacy and Safety of Pregabalin vs Placebo for Generalized Anxiety Disorder (GAD) Symptoms in Subjects Discontinuing Benzodiazepine Treatment and Remaining 6 Weeks on Study Medication, Free From Benzodiazepine Use.

GAD subjects maintained on a stable dose of alprazolam for at least four weeks who meet eligibility criteria will be randomized to receive pregabalin vs matching placebo while simultaneously tapering off of alprazolam over 6 weeks. Subjects return weekly for assessment of safety/tolerability of pregabalin vs placebo as well as for assessment of anxiety and benzodiazepine withdrawal symptoms. Subjects successfully able to discontinue alprazolam, will continue 6 weeks of treatment with pregabalin vs placebo (free of benzodiazepine use). The efficacy and safety of pregabalin vs placebo for anxiety symptoms and ability to discontinue/remain free of alprazolam will be compared among pregabalin and placebo treated groups. Hypothesis is that a greater proportion of subjects will be successful in discontinuing and remaining free from benzodiazepines who were treated with pregabalin as compared to subjects treated with placebo.