Pediatric irritability, defined as increased proneness to anger relative to peers, is among the most common reasons for mental health referrals. The past 15 years have witnessed a dramatic rise in the empirical study of pediatric irritability with the goal of developing more effective methods of assessing and treating these impaired youth. Irritability in Pediatric Psychopathology offers a comprehensive overview of this work, approaching the topic from multiple perspectives and disciplines including child psychiatry, clinical psychology, developmental psychology, and neuroscience. The book has five sections composed of chapters written by international experts. The first section provides an overview of the definition and prevalence of pediatric irritability, current assessment methods, and novel behavioral and psychophysiological indicators of irritability in youth. The second section reviews the literature on the development of pediatric irritability from preschool age through adolescence and young adulthood. The third section summarizes the current evidence for genetic and neurobiological factors contributing to pediatric irritability. The fourth section reviews the presentation of irritability across diagnoses including mood and anxiety disorders, disruptive behavior disorders, and autism. Finally, the fifth section presents evidence-based psychological and pharmacological interventions for pediatric irritability. Irritability in Pediatric Psychopathology is an essential resource for researchers, clinicians, and trainees working with children and adolescents.