Commonly called PDD. Characteristics of this disorder can include – problems with social interactions – problems with verbal communication – limited number of interests. This diagnosis is often used when a clear diagnosis of other disorders are not decided. This can include autism disorder. A neurological disorder seen in children by the age of 3. A child can show problems with eye contact – interacting with others. They may show signs of understanding language and could play with toys in unusual manors. There is no known cure for this disorder. Treatment can include behavioral treatments such as ABA.