• To compare the efficacy of duloxetine 60 mg once-daily versus escitalopram 10 mg once-daily and placebo during acute therapy
• To compare the efficacy of duloxetine 60-120 mg once-daily versus escitalopram 10-20 mg once-daily and placebo for up to 8 months of therapy
• To compare incidence of sexual dysfunction (defined by Changes in Sexual Functioning Questionnaire (CSFQ)), during acute therapy for patients treated with duloxetine 60 mg once-daily versus escitalopram 10 mg once-daily & placebo.
• To compare sexual dysfunction during up to 8 months of treatment with duloxetine 60-120 mg once-daily versus escitalopram 10 to 20 mg once-daily and placebo
• To compare impact of duloxetine 60 mg once-daily versus escitalopram 10 mg once-daily & placebo during acute therapy & during 8 months of therapy on quality of life, functional/health outcomes, & patient satisfaction with study drug
• To compare impact of duloxetine 60-120 mg once-daily versus escitalopram 10 to 20 mg once-daily and placebo for up to 8 months of therapy on quality of life, functional/health outcomes, & patient satisfaction with study drug
• To compare impact of duloxetine 60-120 mg once-daily versus escitalopram 10-20 mg once-daily and placebo during acute and extended therapy on resource utilization (% patients using more,less or equal number of health care providers and services)
• To evaluate safety and tolerability of duloxetine 60 mg once-daily vs. escitalopram 10 mg once-daily and placebo during acute therapy
• To evaluate the safety and tolerability of duloxetine 60-120 mg once-daily vs. escitalopram 10-20 mg once-daily and placebo for up to 8 months of therapy
• To compare percentage of patients taking duloxetine 60 mg once-daily versus escitalopram 10 mg once-daily and placebo requiring a dose escalation due to less than satisfactory initial response (defined by IRB supplement or investigator request)
• To compare efficacy of duloxetine versus escitalopram in the placebo non-responders who enter the rescue phase

The purposes of this study are to determine:

• The safety of duloxetine and any side effects that might be associated with it.
• How duloxetine compares to escitalopram and placebo (an inactive ingredient)

duloxetine 60mg - 120mg, escitalopram 10mg - 20mg, and placebo, 8-month,

• Drug: duloxetine
• Drug: escitalopram
• Drug: placebo

• Prakash A, Risser RC, Mallinckrodt CH. The impact of analytic method on interpretation of outcomes in longitudinal clinical trials. Int J Clin Pract. 2008 Aug;62(8):1147-58. Epub 2008 Jun 28.
• Pigott TA, Prakash A, Arnold LM, Aaronson ST, Mallinckrodt CH, Wohlreich MM. Duloxetine versus escitalopram and placebo: an 8-month, double-blind trial in patients with major depressive disorder. Curr Med Res Opin. 2007 Jun;23(6):1303-18. Epub 2007 Apr 27.
• Nierenberg AA, Greist JH, Mallinckrodt CH, Prakash A, Sambunaris A, Tollefson GD, Wohlreich MM. Duloxetine versus escitalopram and placebo in the treatment of patients with major depressive disorder: onset of antidepressant action, a non-inferiority study. Curr Med Res Opin. 2007 Feb;23(2):401-16.

Inclusion Criteria:

• Must be at least 18 of age
• Must meet the criteria for major depressive disorder
• You must be able to visit the doctor's office about once a week for 2 to 3 months. After that, you will need to visit the doctor's office once a month for about 6 months
• You must be able to take the study drug as prescribed (6 capsules per day taken once-daily)

Exclusion Criteria:

• You are a woman and are pregnant or breastfeeding.
• You have a current or previous major psychiatric disorder other than depression, such as bipolar disorder, schizophrenia, or other psychotic disorder.
• You have a history of alcohol or drug dependence within the past 6 months