Outpatients ( 18 years ) who met criteria for MDD from the Diagnostic and Statistical Manual of Mental Disorders , Fourth Edition , Text Revision and had screening and baseline 17-item Hamilton Depression Rating Scale ( HDRS17 ) total scores 20 were randomly assigned to placebo or desvenlafaxine 50 or 100 mg/d in an 8-week study conducted from October 2011 to August 2012 .