American Psychiatric Association (2000). Diagnostic and Statistical Manual of Mental
Disorders, Fourth Edition, Text Revision.
Washington, DC: American Psychiatric
Association.
Becker, E., Rinck, M., Margraf, J., & Roth, W. (2001). The emotional stroop effect in anxiety disorders. Journal of Anxiety Disorders, 15(3), 147-159.
Chantarujikapong, S., Scherrer, J., Xian, H., Eisen, S., Lyons, M., Goldberg, J. et al.
(2001). A twin study of generalized anxiety disorder symptoms, panic disorder symptoms and post-traumatic stress disorder in men. Psychiatry Research, 103,
133-145.
Chelminski, I., & Zimmerman, M. (2003). Pathological worry in depressed and anxious patients. Journal of Anxiety Disorders, 17(5), 533-546.
Connor, K., & Davidson, J. (1998). Generalized anxiety disorder: neurobiological and pharmacotherapeutic perspectives. Biological Psychiatry, 44(12), 1286-1294.
Culpepper, L. (2002). Generalized anxiety disorder in primary care: Emerging issues in management and treatment. Journal of Clinical Psychiatry, 63(Supp. 8).
Hettema, J., Neale, M., & Kendler, K. (2001). A review and meta-analysis of the genetic epidemiology of anxiety disorders. American Journal of Pyschiatry, 158, 1568-
1578.
Keller, M. (2002). The long-term clinical course of generalized anxiety disorder. Journal of Clinical Psychiatry, 63(Supp. 8)
Kendler, K.S., Davis, C.G., & Kessler, R.C. (1997). The familial aggregation of common psychiatric and substance abuse disorders in the National Comorbidity Survey: A family history study. British Journal of Psychiatry, 170, 541-548.

Kessler, R., DuPont, R., Berglund, P., & Wittchen, H. (1999). Impairment in pure and comorbid generalized anxiety disorder and major depression at 12 months in two national surveys. The American Journal of Psychiatry, 156, 1915-1923.
Kessler, R., McGonagle, K.A., Zhao, S., Nelson, C.B., Hughes, M., Eshleman, M., et al.
(1994). Lifetime and 12-month prevalence of DSM-III-R psychiatric disorders in the United States. Archives of General Psychiatry, 51, 8-19.
Kessler, R., & Wittchen, H. (2002). Patterns and correlates of generalized anxiety disorder in community samples. Journal of Clinical Psychiatry, 63(Supp. 8).
Mendlewicz, J., Papadimitriou, G.N., Wilmotte, J. (1993). Family study of panic disorder: comparison with generalized anxiety disorder, major depression and normal subjects. Psychiatric Genetics, 3, 73-78.
Noyes, R., Clarkson, C., Crowe, R., Yates, W. et al. (1987). A family study of generalized anxiety disorder. American Journal of Psychiatry, 144(8), 1019-1024.
Roemer, L., Molina, S., Litz, B., & Borkovec, T.D. (1997). Preliminary investigation of the role of previous exposure to potentially traumatizing events in generalized anxiety disorder. Depression and Anxiety, 4, 134-138.
Roye, M.A., Neale, M.C., Pedersen, N.L., Mathe, A.A., & Kendler, K.S. (1995). A twin study of generalized anxiety disorder and major depression. Psychological
Medicine, 25, 1037-1049.
Scherrer, J., True, W., Xian, H., Lyons, M., Eisen, S., Goldberg, J., et al. (2000).
Evidence for genetic influences common and specific to symptoms of generalized anxiety disorder and panic. Journal of Affective Disorders, 57, 25-35.

Wittchen, H., Kessler, R., Beesdo, K., Krause, P., Hofler, M., & Hoyer, J. (2002).
Generalized anxiety disorder and depression in primary care: prevalence, recognition, and management. Journal of Clinical Psychiatry, 63(Supp. 8).
Yonkers, K. (2000). Factors predicting the clinical course of generalized anxiety disorder.
The British Journal of Psychiatry, 176, 544-549.
Zuckerman, M. (1999). Vulnerability to Psychopathology. A biosocial model.
Washington, DC: American Psychological Association.