Paroxetine treatment of generalized anxiety disorder: A double-blind, placebo-controlled study

Objective: This study assessed the efficacy of two fixed doses of paroxetine in the treatment of generalized anxiety disorder. Method: Outpatients (N=566) with generalized anxiety disorder and no other axis I disorder were eligible if they scored greater than or equal to20 on the Hamilton Rating Scale for Anxiety (with a score of 2 or higher on the anxious mood and tension items). Following a 1-week placebo run-in phase, patients were randomly assigned to 8 weeks of treatment with paroxetine, 20 or 40 mg/day, or placebo. The primary outcome measure was the change from baseline in total score on the Hamilton anxiety scale. Response was defined as a rating of "very much improved" or "much improved" on the Clinical Global Impression global improvement measure; remission was defined as a Hamilton anxiety scale score less than or equal to7. Change in functional impairment was measured with the Sheehan Disability Scale. Results: At 8 weeks, reductions in total score on the Hamilton anxiety scale were significantly greater for both paroxetine groups. Response was achieved by 62% and 68% of the patients receiving 20 and 40 mg of paroxetine, respectively, compared with a 46% response rate in the placebo group. Remission was achieved by 30% and 36% of patients in the 20- and 40-mg paroxetine groups, respectively, compared with 20% given placebo. For all three domains of the Sheehan Disability Scale, significantly greater improvement was seen with paroxetine than placebo. Both doses of paroxetine were well tolerated. Conclusions: This study demonstrates that paroxetine is an efficacious and well-tolerated treatment for generalized anxiety disorder.