I highly recommend the use of this book by teens with chronic worry and anxiety as well as for professionals who work with anxious youth - great supplement! (newharbinger.com)
Salivary oxytocin in clinically anxious youth: associations with separation anxiety and family accommodation (cambridge.org)
Accumulating evidence from clinical and nonclinical samples shows that socially anxious youth are more rejected and less liked by, and receive more negative treatment from peers than their nonanxious counterparts (e.g., Blöte et al. 2007; Spence et al. 1999; Verduin and Kendall 2008). (link.springer.com)