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-controlled study was to investigate theefficacy and safety of paroxetine in outpatients with generalizedanxiety disorder (GAD).

Method: Male and female outpatients 18 years andolder who met DSM-IV criteria for GAD and had baseline scores ofat least 20 on the Hamilton Rating Scale for Anxiety (HAM-A) wererandomly assigned to treatment with paroxetine (20-50 mg/day) orplacebo for 8 weeks. The primary efficacy variable was the meanchange from baseline in the total score of the HAM-A. Additionalkey efficacy variables were the change from baseline in thescores of the HAM-A items anxious mood and tension, the anxietysubscale of the Hospital Anxiety and Depression Scale, and theSheehan Disability Scale (SDS). The proportions of patientsfulfilling response and remission criteria at week 8 were alsodetermined.

Results: The intent-to-treat population included324 patients. At week 8, compared with the placebo group (N =163), the paroxetine group (N = 161) had a significantly greaterreduction of GAD symptoms on all of the above-mentioned efficacyvariables. On the HAM-A anxious mood item, which encompasses thecardinal symptoms of GAD, significantly greater efficacy wasobserved from week 1 and on the SDS significantly greaterimprovement was documented in the domain “social life”as early as week 4 for paroxetine compared with placebo. In boththe last-observation-carried-forward and completer data sets,significantly greater proportions of paroxetine-treated patientsachieved response or remission by week 8. Treatment withparoxetine was well tolerated, and the number and type of adverseevents recorded in the paroxetine group correspond to the knownsafety profile of this medication.

Conclusion: Paroxetine in doses of 20 to 50 mgonce daily is effective in the treatment of patients with GAD.Improvement of core symptoms of GAD occurs early and isassociated with significant reduction in disability after only 8weeks of treatment.