Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A developmental disorder is any condition that appears at some stage in a child's development and delays the development of one or more psychological functions, such as language skill. Developmental disorders include psychological and physical disorders, for example autism or dyslexia. Developmental disorders are an impairment in the normal development of motor or cognitive skills that are developed before age 22. They are usually expected to continue indefinitely, and there usually is no cure. Learn more about developmental disorders, their causes and treatment options in this book.