Dose-Response Efficacy of Paroxetine in Preventing Depressive Recurrences: A Randomized, Double-Blind Study

Background: The authors evaluated and compared the efficacy of 20 mg versus 40 mg of paroxetine in a randomized, double-blind, parallel-group study during a maintenance period of 28 months.

Method: Ninety-nine inpatients with recurrent, unipolar depression (DSM-IV criteria) who had at least 1 depressive episode during the 18 months preceding the index episode were openly treated with paroxetine 40 mg/day. Seventy-two subjects had a stable response (Hamilton Rating Scale for Depression score <8) to paroxetine treatment and remained in the continuation treatment as outpatients for 4 months. At the time of recovery, 68 patients were randomly assigned to 1 of the 2 maintenance treatment groups: paroxetine 20 mg or paroxetine 40 mg daily.

Results: Sixty-seven patients completed the 28-month follow-up period. Seventeen (51.5%) of 33 patients in the 20-mg paroxetine regimen had a single recurrence compared with 8 (23.5%) of 34 subjects in the 40-mg dose regimen (c²=5.56, p=.018).

Conclusion: These data suggest that a full dose of paroxetine is recommended in unipolar patients who are at high risk for recurrent depressive episodes.