This study assessed the efficacy of desvenlafaxine 50 mg/day compared with 
placebo for treating moderate or severe major depressive disorder (MDD). Data 
were pooled from six double-blind, placebo-controlled, desvenlafaxine 50 mg/day 
fixed-dose studies in adults with MDD. The primary endpoint was improvement in 
17-item Hamilton Rating Scale for Depression (HAM-D17) scores from baseline at 
week 8. HAM-D17 changes were evaluated in patients with moderate (18<HAM-D17<25) 
or severe (HAM-D17≥25) MDD at baseline using analysis of covariance with 
treatment, study, and baseline in the model. The pooled analysis included 2189 
patients (desvenlafaxine 50 mg, n=1150; placebo, n=1039). Of those, 694 (32%) 
patients had severe depression at baseline. Desvenlafaxine improved HAM-D17 
scores versus placebo in patients with either moderate [desvenlafaxine, adjusted 
mean (±SE), -10.26±0.24; placebo, -8.87±0.26; P<0.001] or severe MDD 
(desvenlafaxine, -11.91±0.40; placebo, -9.85±0.42; P<0.001). Both moderately and 
severely depressed patients had significantly higher rates of response and 
remission with desvenlafaxine treatment compared with placebo (all P's≤0.029). 
Results were similar when baseline severity was defined by Montgomery-Åsberg 
Depression Rating Scale or Sheehan Disability Scale scores. Desvenlafaxine 50 
mg/day significantly improved depressive symptoms regardless of severity at 
baseline and was effective in treating both moderate and severe MDD.