Eric A. Youngstrom, PhD, is Professor of Psychology and Neuroscience and Professor of Psychiatry at the University of North Carolina at Chapel Hill, where he is also Acting Director of the Center for Excellence in Research and Treatment of Bipolar Disorder. He was the inaugural recipient of the Early Career Award from the Society of Clinical Child and Adolescent Psychology of the American Psychological Association (APA), and is an elected full member of the American College of Neuropsychopharmacology. Dr. Youngstrom has consulted on DSM-5 and ICD-11. He is past president of the Society for Clinical Child and Adolescent Psychology and currently chairs the Work Group on Child Diagnosis for the International Society for Bipolar Disorders and serves as President (2020) of APA Division 5, Quantitative and Qualitative Methods. Mitchell J. Prinstein, PhD, ABPP, is the John Van Seters Distinguished Professor of Psychology and Neuroscience at the University of North Carolina at Chapel Hill. His research examines interpersonal models of internalizing symptoms and health-risk behaviors among adolescents, with a focus on the unique role of peer relationships in the developmental psychopathology of depression, self-injury, and suicidality. An Associate Editor of the Journal of Consulting and Clinical Psychology and a member of the National Institutes of Health's Study Section on Psychosocial Development, Risk, and Prevention, Dr. Prinstein is a recipient of the Theodore Blau Early Career Award from the Society of Clinical Psychology of the American Psychological Association (APA), among other honors. He is a Fellow of the APA Society of Clinical Child and Adolescent Psychology. Eric J. Mash, PhD, is Professor Emeritus of Psychology at the University of Calgary and Affiliate Professor in the Department of Psychiatry at Oregon Health and Science University. He is a Fellow of the Canadian Psychological Association and of the Society of Clinical Psychology, the Society for Child and Family Policy and Practice, the Society of Clinical Child and Adolescent Psychology, and the Society of Pediatric Psychology of the American Psychological Association. Dr. Mash is also a Fellow and Charter Member of the Association for Psychological Science. He has served as an editor, editorial board member, and editorial consultant for numerous journals and has published widely on child and adolescent psychopathology, assessment, and treatment. Russell A. Barkley, PhD, ABPP, ABCN, is Clini