Anxiety disorders are among the most prevalent mental health problems in childhood and adolescence. This fully revised new edition is an authoritative guide to the understanding and assessment of anxiety disorders in the young. The first section covers historical and conceptual issues, including cognitive and developmental processes, clinical and theoretical models, phenomenology and classification, and evidence-based assessment. Subsequent sections cover the biology of child and adolescent anxiety, and environmental influences including traumatic events, parenting and the impact of the peer group. The final section addresses prevention and treatment of anxiety. All chapters incorporate new advances in the field, explicitly differentiate between children and adolescents, and incorporate a developmental perspective. Written and edited by an international team of leading experts in the field, this is a key text for researchers, practitioners, students and clinical trainees with interests in child and adolescent anxiety.