Alex KD, Pehek EA (2007). Pharmacologic mechanisms of serotonergic regulation of dopamine neurotransmission. Pharmacology and Therapeutics 113, 296–320.
APA (1994). Diagnostic and Statistic Manual of Mental Disorders, 4th edn. American Psychiatric Association: Washington, DC.
Beck AT, Emery G, Greenberg RL (1985). Anxiety Disorders and Phobias: A Cognitive Perspective. Basic Books: New York.
Behar E, Alcaine O, Zuellig AR, Borkovec TD (2003). Screening for generalized anxiety disorder using the Penn State Worry Questionnaire: a receiver operating characteristic analysis. Journal of Behavior Therapy and Experimental Psychiatry 34, 25–43.
Borkovec TD (1994). The nature, functions, and origins of worry. In Worrying: Perspectives on Theory, Assessment and Treatment (ed. Davey G. and Tallis F.), pp. 5–33. Wiley: Chichester, UK.
Borkovec TD, Inz J (1990). The nature of worry in generalized anxiety disorder: a predominance of thought activity. Behaviour Research and Therapy 28, 153–158.
Borkovec TD, Ray WJ, Stober J (1998). Worry: a cognitive phenomenon intimately linked to affective, physiological, and interpersonal behavioral processes. Cognitive Therapy and Research 22, 561–576.
Brown TA, O'Leary TA, Barlow DH (2001). Generalised anxiety disorder. In Clinical Handbook of Psychological Disorders: A Step-by-Step Treatment Manual (ed. Barlow I. D. H.), pp. 154–208. Guilford Press: New York.
Dinstein I, Thomas C, Behrmann M, Heeger DJ (2008). A mirror up to nature. Current Biology 18, R13–R18.
Frankle WG, Laruelle M, Haber SN (2006). Prefrontal cortical projections to the midbrain in primates: evidence for a sparse connection. Neuropsychopharmacology 31, 1627–1636.
Fresco DM, Frankel AN, Mennin DS, Turk CL, Heimberg RG (2002). Distinct and overlapping features of rumination and worry: the relationship of cognitive production to negative affective states. Cognitive Therapy and Research 26, 179–188.
Fresco DM, Mennin DS, Heimberg RG, Turk CL (2003). Using the Penn State Worry Questionnaire to identify individuals with generalized anxiety disorder: a receiver operating characteristic analysis. Journal of Behavior Therapy and Experimental Psychiatry 34, 283–291.
Frison L, Pocock SJ (1992). Repeated measures in clinical trials: analysis using mean summary statistics and its implications for design. Statistics in Medicine 11, 1685–1704.
Friston KJ, Frith CD, Turner R, Frackowiak RS (1995). Characterizing evoked hemodynamics with fMRI. Neuroimage 2, 157–165.
Friston KJ, Holmes AP, Worsley KJ (1999). How many subjects constitute a study? Neuroimage 10, 1–5.
Frith CD, Frith U (1999). Interacting minds: a biological basis. Science 286, 1692–1695.
Frith CD, Frith U (2006). The neural basis of mentalizing. Neuron 50, 531–534.
Gallese V, Fadiga L, Fogassi L, Rizzolatti G (1996). Action recognition in the premotor cortex. Brain 119, 593–609.
Hoehn-Saric R, McLeod DR, Zimmerli WD (1988). Differential effects of alprazolam and imipramine in generalized anxiety disorder: somatic versus psychic symptoms. Journal of Clinical Psychiatry 49, 293–301.
Hoehn-Saric R, Schlund MW, Wong SH (2004). Effects of citalopram on worry and brain activation in patients with generalized anxiety disorder. Psychiatry Research 131, 11–21.
Iacoboni M, Woods RP, Brass M, Bekkering H, Mazziotta JC, Rizzolatti G (1999). Cortical mechanisms of human imitation. Science 286, 2526–2528.
Meyer TJ, Miller ML, Metzger RL, Borkovec TD (1990). Development and validation of the Penn State Worry Questionnaire. Behaviour Research and Therapy 28, 487–495.
Newman MG, Zuellig AR, Kachin KE, Constantino MJ, Przeworski A, Erickson T, Cashman-McGrath L (2002). Preliminary reliability and validity of the Generalized Anxiety Disorder Questionnaire-IV: a revised self-report diagnostic measure of generalized anxiety disorder. Behavior Therapy 33, 215–233.
Pollack MH, Zaninelli R, Goddard A, McCafferty JP, Bellew KM, Burnham DB, Iyengar MK (2001). Paroxetine in the treatment of generalized anxiety disorder: results of a placebo-controlled, flexible-dosage trial. Journal of Clinical Psychiatry 62, 350–357.
Pratt P, Tallis F, Eysenck M (1997). Information-processing, storage characteristics and worry. Behaviour Research and Therapy 35, 1015–1023.
Ramnani N, Owen AM (2004). Anterior prefrontal cortex: insights into function from anatomy and neuroimaging. Nature Reviews Neuroscience 5, 184–194.
Schönpflug W (1989). Anxiety, worry, prospective orientation, and prevention. In Stress and Anxiety (ed. Spielberger C. D. and Sarason I. G.), pp. 245–258. Hemisphere: Washington, DC.
Segerstrom SC, Tsao JCI, Alden LE, Craske MG (2000). Worry and rumination: repetitive thought as a concomitant and predictor of negative mood. Cognitive Therapy and Research 24, 671–688.
Watkins E, Moulds M, Mackintosh B (2005). Comparisons between rumination and worry in a non-clinical population. Behaviour Research and Therapy 43, 1577–1585.
Williams SM, Goldman-Rakic PS (1998). Widespread origin of the primate mesofrontal dopamine system. Cerebral Cortex 8, 321–345.