This randomised, double-blind fixed-dose study compared the efficacy of escitalopram and paroxetine in the long-term treatment of patients with severe MDD.

Patients with DSM-IV-defined MDD and baseline Montgomery-Åsberg Depression Rating Scale (MADRS ≥30) were randomised in a 1:1 ratio to 24 weeks of double-blind treatment with either escitalopram (20mg) or paroxetine (40mg). The primary analysis of efficacy was an analysis of covariance of change from baseline to Week 24 in MADRS total score using the last observation carried forward (LOCF) method.

At endpoint (24 weeks), the mean change from baseline in total MADRS score was -25.2 for escitalopram-treated patients (n=228) and -23.1 for paroxetine-treated patients (n=223), a difference of 2.1 points (p<0.05). The difference on the MADRS (LOCF) was significantly in favour of escitalopram from Week 8 onwards. Response rates (≥50% decrease in MADRS) after 24 weeks were 82% (escitalopram) and 77% (paroxetine). Remission rates (MADRS ≤12) were 75% (escitalopram) and 67% (paroxetine) (p<0.05). These results were supported by a significantly greater difference in favour of escitalopram on all secondary efficacy analyses. For very severely depressed patients (baseline MADRS ≥35), there was a difference of 3.5 points in favour of escitalopram (p<0.05) at endpoint (24 weeks). The overall withdrawal rate for patients treated with escitalopram (19%) was significantly lower than with paroxetine (32%) (p<0.01). The withdrawal rate due to AEs was significantly lower for escitalopram (8%) compared to paroxetine (16%) (p<0.05).

Escitalopram was significantly more effective than paroxetine in the treatment of patients with severe MDD.