CONTROLLED EFFICACY STUDY OF FLUOXETINE IN DYSTHYMIA

Background There have been very few controlled studies of antidepressa nts in dysthymia, particularly in samples diagnosed reliably and with an adequate length of follow-up, in this investigation, we measured th e long-term outcome in a large group of patients meeting DSM-III-R cri teria for dysthymia. This study was designed to investigate whether fl uoxetine is effective in the treatment of dysthymia. Method This rando mised study, including 140 patients, compared fluoxetine (91 patients) and placebo (49 patients) on a double-blind basis in two distinct pha ses: a short-term end-point (3 months with 20 mg/day fluoxetine) and a medium-term end-point (6 months) where the initial responders continu ed double-blind treatment unchanged and non-responders received an add itional treatment of 20 mg/day fluoxetine. Results After-three months of treatment, response was seen more frequently in the fluoxetine grou p (42/72) than in the placebo group (14/39,P < 0.0001). Improved patie nts at 3 months were still improved at 6 months. Furthermore 50% of th e non-responders art 3 months improved and rated as responders at 6 mo nths, after fluoxetine was increased to 40 mg daily. Conclusions This study showed the significant and persistent action of fluoxetine on dy sthymia. The finding that 50% of the non-responders at 3 months were i mproved at 6 months, after fluoxetine dosage was increased to 40 mg da ily, argues in favour of treating dysthymic patients for at least 6 mo nths, and with a higher dosage if the initial doses are ineffective.