To determine if duloxetine works just as well as paroxetine in the treatment of major depressive disorder.

Inclusion Criteria:

• You are male or female at least 18 years of age with nonpsychotic major depression. Females of child-bearing potential must test negative on a pregnancy test at visit 1.

Exclusion Criteria:

• You have a serious medical illness, including any cardiovascular, hepatic, renal, respiratory, hematologic, endocrinologic, or neurologic disease, or clinically significant laboratory abnormality.
• You have a history of hepatic dysfunction, current jaundice, or positive hepatitis B surface Antigen or positive hepatitis C surface Antibody regardless of ALT.
• You have an ALT greater than or equal to 2 times the upper limit of normal.
• You have abnormal thyroid-stimulating hormone concentrations.