Background: Citalopram is a racemic selective serotonin reuptake inhibitor (SSRI) indicated for the treatment of depression. Citalopram is a racemate and its serotonin reuptake inhibitory activity resides primarily in the single S-isomer, escitalopram, which is now being evaluated for its potential usefulness in the treatment of depression and other psychiatric disorders. Results from placebo-controlled studies that also included Citalopram as an active control have shown that escitalopram is effective in treating depression and associated symptoms of anxiety. However, none of these studies was powered sufficiently to detect differences between active treatment groups. The goal of the present analysis is to evaluate the efficacy of escitalopram compared with Citalopram in the treatment of major depressive disorder.
Method: Data were pooled from three similarly designed, randomized, double-blind, placebo-controlled trials of escitalopram (10–20 mg/day) and Citalopram (20–40 mg/day). Patients were male or female, ≥18 years of age, who met criteria for a major depressive episode with a Montgomery Asberg Depression Rating Scale (MADRS) score ≥22 at baseline. Efficacy measures included change from baseline in MADRS score and the Clinical Global Impression of Improvement (CGI-I) scale. Improvement in associated symptoms of anxiety was measured using the change from baseline in the MADRS inner tension item.
Results: Both escitalopram and Citalopram significantly improved depression and anxiety symptoms compared with placebo, and there were significantly more MADRS responders (defined as ≥50% improvement in MADRS scores at end point) in the escitalopram and Citalopram treatment groups. Escitalopram treatment was associated with statistically significant improvements in all efficacy measures relative to placebo after 1 week of treatment, whereas Citalopram treatment statistically separated from placebo at the end of week 4 (CGI-I and MADRS inner tension) or week 6 (MADRS). Escitalopram treatment also was statistically significantly superior to Citalopram treatment at a number of time points.
Conclusion: These data support the effectiveness of escitalopram and Citalopram in the treatment of major depressive disorder, and suggest escitalopram may have a faster onset and greater overall magnitude of effect than citalopram in improving symptoms of depression and anxiety in patients with major depressive disorder.