A randomized double-blind comparison of fluoxetine augmentation by high and low dosage folic acid in patients with depressive episodes

Abstract

Background: Though encouraging evidence exists for the use of folic acid as an augmenting agent to antidepressants, evidence regarding its optimal dosage is lacking.

Methods: Forty-two female out-patients with moderate (with or without somatic syndrome) or severe depressive episodes (without psychotic symptoms) diagnosed as per ICD-10 criteria, were randomized in a double-blind fashion to receive either 20 mg fluoxetine and a relatively low dose folic acid (1.5 mg/day; n=23; Group I) or 20 mg fluoxetine and high dose folic acid (5 mg/day; n=19; Group II). Primary outcome measures were weekly changes of scores on Hamilton Depression Rating Scale (HDRS) and Beck Depression Inventory (BDI) for 6 weeks.

Results: Group II patients showed greater improvement in both HDRS [Mean (SD) baseline HDRS score=21 (2.3) for group I and 20.0 (1.4) for group-II; time X group interaction effect: p=0.01] and BDI [Mean (SD) baseline BDI score=25.1 (5.2) for group-1 and 23.1 (2.7) for group-II; time X group interaction effect: p=0.01]. With regard to HDRS, 7 (36.8%) group II patients remitted compared to 2 (8.7%) group I patients (p=0.03); 9 (47.4%) patients of group II responded when compared to 6 (26.1%) from group I (p=0.15). When BDI was considered, 5 (26.3%) group II patients remitted when compared to 2 (8.7%) from group I (p=0.13); 10 patients (52.6%) from group II responded when compared to 5 (21.7%) from group I (p=0.04). No adverse effects were noted in either group.

Limitations: Lack of a placebo arm and small sample size.

Conclusion: Compared to folic acid 1.5 mg/day, augmentation with 5 mg/day may be more beneficial in female patients with depressive episodes taking fluoxetine 20 mg/day.

Keywords: Augmentation; Depressive episodes; Fluoxetine; Folate; Folic acid.