Here are some books/sites that might help anyone looking into 'mindfulness cognitive behaviour therapy.' Jon Kabat-Zinn seems to be the main author of a number of books about this and parenting. Some help seems to be aimed at the child re anxiety and others at the parent re how to deal with children's emotions. My son's psychologist says there are also some CDs that use this method that are good for both parent and child suffering anxiety or depression.

There is also a free on-line Mood Gym that was created from University researches in Australia that might help some of your teenage children.
http://moodgym.anu.edu.au/welcome

Mindfulness-Based Cognitive Therapy for Anxious Children: A Manual for Treating Childhood Anxiety, by Randye Semple, Jennifer Lee. New Harbinger Pubns Inc, 2010. ISBN 1572247193.

The Mindfulness and Acceptance Workbook for Anxiety: A Guide to Breaking Free from Anxiety, Phobias, and Worry Using Acceptance and Commitment Therapy by John P. Forsyth and Georg H. Eifert.

http://mbct.co.uk/about-mbct/

Mindfulness Based Cognitive Therapy in Boston: "http://www.mbctboston.com/