Child psychopathology refers to the scientific study of mental disorders in children and adolescents. Oppositional defiant disorder, attention-deficit hyperactivity disorder, and autism spectrum disorder are examples of psychopathology that are typically first diagnosed during childhood. Mental health providers who work with children and adolescents are informed by research in developmental psychology, clinical child psychology, and family systems. Lists of child and adult mental disorders can be found in the International Statistical Classification of Diseases and Related Health Problems, 10th Edition (ICD-10), published by the World Health Organization (WHO) and in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), published by the American Psychiatric Association (APA). In addition, the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood is used in assessing mental health and developmental disorders in children up to age five.