Urope. Eur Neuropsychopharmacol 2005, 15:445?52. 3. Kessler RC, DuPont RL, Berglund P, Wittchen HU: Impairment in pure and comorbid generalized anxiety disorder and major depression at 12 months in two national surveys. Am J Psychiatry 1999, 156:1915?923. 4. Hoffman DL, Dukes E, Wittchen HU: Human and economic burden of generalized anxiety disorder. Depress Anxiety 2008, 25:72?0. 5. Wittchen HU: G