Generalized anxiety disorder is characterized by excessive worry about 2 or more life circumstances for a period of 6 months or longer. Biological and genetic factors may combine with stress to produce psychological symptoms. Update Date: 02/06/2008Christos Ballas, MD, Attending Psychiatrist, Hospital of the University of Pennsylvania, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.