Onset of Action of Escitalopram Compared with Other Antidepressants: Results of a Pooled Analysis

In general, antidepressant drugs are regarded as too slow acting. Most patients who benefit from treatment require more than 2 weeks of therapy to respond to treatment. An efficacious and well-tolerated antidepressant drug with an earlier onset of effect would be of greater interest to clinicians and patients. To study the onset of effect of escitalopram, a selective serotonin reuptake inhibitor (SSRI), data were pooled from controlled randomized clinical double-blind trials comparing this drug with other antidepressant drugs (SSRIs and venlafaxine XR) in major depressive disorder (MDD), with assessments of the primary efficacy parameter [mean change in the Montgomery-Asberg Depression Rating Scale (MADRS) total score from baseline, using last observation carried forward]. The mean change in MADRS total scores was significantly higher for escitalopram-treated patients than for patients treated with the comparators on day 7 (-3.9 versus -3.4, respectively, P = 0.029). This difference remained significant and in favour of escitalopram at all subsequent assessments. Using secondary outcomes (Clinical Global Impression of Improvement and Severity scales and early improvement), the results consistently showed a statistically significantly faster onset of effect of escitalopram compared to other antidepressants. In conclusion, by using the MADRS scale and pooling data from the escitalopram clinical trials in MDD comparing escitalopram with other active antidepressant drugs, escitalopram was shown to be a fast-acting antidepressant with a more rapid onset of effect than the comparators, particularly other SSRIs.