Generalized anxiety disorder (GAD) is characterized by pervasive worry that is difficult to control leading to exhausting hypervigilance, multiple somatic symptoms and impaired social and occupational functioning. Recent estimates suggest that GAD affects 3% of the population in any one year and 5-8% of the population over the course of their lifetimes. A study of 327 people in the U.S. looked at the effectiveness of the Selective Serotonin Reuptake Inhibitor (SSRI) duloxetine on GAD. Over ten weeks 168 of the participants were given duloxetine and 159 a placebo. By the end of the trial those patients given duloxetine were less anxious and showed a higher response rate and greater improvement than those participants who had been given a placebo. They also suffered from less impairment in work, family and social situations. However, people were more likely to stop taking duloxetine because of side effects which included nausea, dizziness and somnolence.
Rynn, Moira ... [et al] - Efficacy and safety of duloxetine in the treatment of generalized anxiety disorder: a flexible dose, progressive-titration, placebo-controlled trial Depression and Anxiety 2008, 25(3), 182-189