This is a clinical trial assessing duloxetine and comparator to placebo in patients who have generalized anxiety disorder.

Inclusion Criteria:

• Male and female outpatients at least 18 years of age, presenting with generalized anxiety disorder (GAD).

Exclusion Criteria:

• Any current and primary Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) Axis I diagnosis other than GAD. Patients diagnosed with major depressive disorder within the past 6 months -or- patients diagnosed with panic disorder, post-traumatic stress disorder, or an eating disorder within the past year -or- obsessive-compulsive disorder, bipolar affective disorder, psychosis factitious disorder, or somatoform disorders during their lifetime
• The presence of an Axis II disorder or history of antisocial behavior, which in the judgement of the investigator would interfere with compliance with study protocol
• Have previously completed or withdrawn from this study or any other study investigating duloxetine or have previously been treated with duloxetine
• History of alcohol or any psychoactive substance abuse or dependence (as defined in the DSM-IV-TR) within the past 6 months