Paroxetine in the treatment of generalized anxiety disorder: Results of a placebo-controlled, flexible-dosage trial

Background: The objective of this randomized, double-blind, placebo-control led study was to investigate the efficacy and safety of paroxetine in outpa tients with generalized anxiety disorder (GAD). Method: Male and female outpatients 18 years and older who met DSM-IV crite ria for GAD and had baseline scores of at least 20 on the Hamilton Rating S cale for Anxiety (HAM-A) were randomly assigned to treatment with paroxetin e (20-50 mg/day) or placebo for 8 weeks. The primary efficacy variable was the mean change from baseline in the total score of the HAM-A. Additional k ey efficacy variables were the change from baseline in the scores of the HA M-A items anxious mood and tension, the anxiety subscale of the Hospital An xiety and Depression Scale, and the Sheehan Disability Scale (SDS). The pro portions of patients fulfilling response and remission criteria at week 8 w ere also determined. Results: The intent-to-treat population included 324 patients. At week 8, c ompared with the placebo group (N = 163), the paroxetine group (N = 161) ha d a significantly greater reduction of GAD symptoms on all of the above-men tioned efficacy variables. On the HAM-A anxious mood item, which encompasse s the cardinal symptoms of GAD, significantly greater efficacy was observed from week 1 and on the SDS significantly greater improvement was documente d in the domain "social life" as early as week 4 for paroxetine compared wi th placebo. In both the last-observation-carried-forward and completer data sets, significantly greater proportions of paroxetine-treated patients ach ieved response or remission by week 8. Treatment with paroxetine was well t olerated, and the number and type of adverse events recorded in the paroxet ine group correspond to the known safety profile of this medication. Conclusion: Paroxetine in doses of 20 to 50 mg once daily is effective in t he treatment of patients with GAD. Improvement of core symptoms of GAD occu rs early and is associated with significant reduction in disability after o nly 8 weeks of treatment.