[Page 252]As with most emotional disorders, anxiety disorders in childhood have been linked to a combination of biological and environmental causes. Advances in cognitive neuroscience, genetics, and brain imaging have significantly contributed to current understanding of the neurobiological correlates of anxiety disorders in youth. This entry describes current thinking about the biological contributors to anxiety in childhood, including genetic contributions, the role of neural circuits and neurotransmitters in anxiety, as well as a summary of findings from brain imaging studies that have influenced current understanding of how anxiety arises and is maintained. The entry concludes with a summary of the many ways these biological factors are thought to interact with other etiological contributors to anxiety, such as psychological, social, and environmental factors. Thus, biological factors ...