To assess the efficacy of Duloxetine compared with placebo in the treatment of pain in patients with Fibromyalgia syndrome, with or without major depressive disorder.

Inclusion Criteria:

• Meet criteria for primary Fibromyalgia Syndrome as defined by the American College of Rheumatology

Exclusion Criteria:

• Have any current primary Axis I diagnosis other than major depressive disorder
• Have any current or previous diagnosis of psychosis, bipolar disorder, or schizoaffective disorder
• Have any primary diagnosis of anxiety disorder within the past year (including panic disorder, agoraphobia, OCD, PTSD, GAD and social phobia)
• Have regional pain syndrome, multiple surgeries or failed back syndrome
• Have a confirmed current or previous diagnosis of rheumatoid arthritis, inflammatory arthritis, or infective arthritis, or an autoimmune disease (e.g. lupus)