• Reduction in average pain severity as measured by an 11-point Likert scale.
  

• Pain severity for worst pain and night pain as measured by an 11-point Likert scale.
  
• Clinical Global Impression of Severity scale to measure severity of illness at the time of assessment.
  
• Patient Global Impression of Improvement scale to measure the degree of improvement at the time of assessment.
  
• Brief Pain Inventory to measure the severity of pain.
  
• Sensory Portion of the Short Form McGill pain questionnaire measures severity of 11 pain descriptors.
  
• Hamilton Depression Rating Scale (17 item) used to assess severity of depression symptoms during the course of therapy.
  
• Dynamic Allodynia measure to elicit the pain severity to a normally non-painful stimulus.
  

The protocol will assess the efficacy and safety of duloxetine. It will also look at how duloxetine affects quality of life.

Inclusion Criteria:

• Male or female outpatients at least 18 years of age.
• Patients with pain due to diabetic neuropathy in both legs.
• Females must not be pregnant or plan to become pregnant during the study.
• Stable Glycemic control.
• Average mean pain severity score of at least 4.0 as assessed by completion of a daily diary.

Exclusion Criteria:

• You are related to or work for the physician conducting the study or are employed by Eli Lilly and Company.
• You have a severe or serious medical condition that causes you to be hospitalized often; or you have had a kidney transplant or are on current dialysis.
• You have participated in a study for an investigational drug within the last 30 days.
• You have a history of major depressive disorder, generalized anxiety disorder, or alcohol or eating disorders.
• You have a past medical history or diagnosis of mania, bipolar disorder, or psychosis.