The Influence of Baseline Severity on Efficacy of Escitalopram and Citalopram in the Treatment of Major Depressive Disorder: An Extended Analysis

Objective: To determine the differences between escitalopram and citalopram in the treatment of patients with major depressive disorder across a range of baseline severity of depression using trend analysis. Methods: Data from the three placebo-controlled studies comparing escitalopram to citalopram were analyzed. The pre-specified primary outcome variable was MADRS total score; secondary outcomes included Clinical Global Impression-Severity (CGI-S) and -Improvement (CGI-I) scores. All analyses were based on an intent-to-treat (ITT) population and all direct comparisons were done by ANCOVA adjusting for baseline value and centre. Results: Analyses of the pooled data (N=1203) show that, while the difference between citalopram and placebo was approximately constant across the range of baseline severity, the difference between escitalopram and placebo (p=0.0010 for no trend) and between escitalopram and citalopram (p=0.0012 for no trend) became greater, the more severely depressed the patients were at baseline. A similar pattern was apparent with the CGI-S and CGI-I results. There was a significant superiority of escitalopram over citalopram in response rate (defined as ≥50% decrease in MADRS total score), and this difference increased with increasing baseline severity. Conclusion: These trend analyses thus indicate that the superiority of escitalopram over citalopram is more apparent as the baseline severity of depression increases.

References

• 1 Auquier P, Robitail S, Llorca PM, Rive B. Comparison of escitalopram and citalopram efficacy: a meta-analysis.  Int J Psych Clin Pract. 2003;  7 259-268
• 2 Bech P, Tanghøj P, Cialdella P, Andersen HF, Pedersen AG. Escitalopram dose-response revisited: an alternative psychometric approach to evaluate clinical effects of escitalopram compared to citalopram and placebo in patients with major depression.  Int J Neuropsychopharmacol. 2004;  7 283-290
• 3 Burke WJ, Gergel I, Bose A. Fixed-dose trial of the single isomer SSRI escitalopram in depressed outpatients.  J Clin Psychiatry. 2002;  63 331-336
• 4 Gorman J, Korotzer A, Su G. Efficacy Comparison of escitalopram and citalopram in the treatment of major depressive disorder: pooled analysis of placebo-controlled trials.  CNS Spectr. 2002;  7 ((4 Suppl 1)) 40-44
• 5 Kennedy SH, Andersen HF, Lam RW. Efficacy of escitalopram in the treatment of major depressive disorder compared with conventional selective serotonin reuptake inhibitors and venlafaxine XR: a meta-analysis.  J Psychiatry Neurosci. 2006;  31 122-131
• 6 Lepola UM, Loft H, Reines EH. Escitalopram (10-20 mg/day) is effective and well tolerated in a placebo-controlled study in depression in primary care.  Int Clin Psychopharmacol. 2003;  18 211-217
• 7 Lepola U, Wade A, Andersen HF. Do equivalent doses of escitalopram and citalopram have similar efficacy? A pooled analysis of two positive placebo-controlled studies in major depressive disorder.  Int Clin Psychopharmacol. 2004;  19 149-155
• 8 Llorca PM, Azorin JM, Despiegel N, Verpillat P. Efficacy of escitalopram in patients with severe depression: a pooled analysis.  Int J Psych Clin Pract. 2005;  59 268-275
• 9 Montgomery SA, Åsberg M. A new depression scale designed to be sensitive to change.  Br J Psychiatry. 1979;  134 382-389
• 10 Moore N, Verdoux H, Fantino B. Prospective, multicentre, randomized, double-blind study of the efficacy of escitalopram versus citalopram in outpatient treatment of major depressive disorder.  Int Clin Psychopharmacol. 2005;  20 131-137
• 11 Rapaport MH, Bose A, Zheng H. Escitalopram continuation treatment prevents relapse of depressive episodes.  J Clin Psychiatry. 2004;  65 44-49

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