Rationale: We are doing this study because many children with autism spectrum disorder (ASD) also have language delays. In some school-age children with ASD, language delay is severe. These children may have only a few words or no words. These children need intensive language therapy. Other children have words, but have trouble speaking in sentences. Some children may try to speak in sentences, but the sentences may be odd in form and difficult to understand. These children may mix up "I" and "you" or show other unusual speech patterns. Still other children speak in repetitive phrases perhaps borrowed from a cartoon or movie. Problems using words to communicate everyday matters are called expressive language delays. Some children may also have problems with understanding simple instructions. These are called receptive language delays. We classify troubles speaking in sentences, using odd ways of speaking, using repetitive phrases, or difficulty with understanding everyday speech as moderate language delays. This study is focused on children who have moderate language delays, which affect up to 50% of children with ASD. Moderate language delays in children with ASD get in the way of learning, add to social disability, and may contribute to behavioral problems. Available research indicates that children with moderate language delays are unlikely to "grow out of it" and may fall further behind.

Intervention: The study will evaluate a program called Direct Instruction - Language for Learning (DI-LL). This program has been used for over 15 years and has been effective in helping children with language problems. Surprisingly, it has not been carefully studied in children with ASD. The 150 lessons in DI-LL are usually given one-on-one with the child by a trained instructor. The instructors are taught to follow the lessons step by step. The lessons are actually scripted in a clear and concise way. This approach ensures that the lessons are given in a consistent manner. Over the 24 weeks of treatment, increasingly complex skills are broken down into parts that build upon each other. Each skill is taught until the child "gets it" and is ready to move on to the next skill. DI-LL actively engages the child in naming objects, putting objects into categories, and building sentences. We selected DI-LL for this project because it is a relatively inexpensive, commercially available program that is designed to address moderate language delays. Another advantage of DI-LL is that it can be delivered by a wide range of practitioners such as educators, psychologists, speech pathologists, and behavior therapists. Thus, if it is effective for children with ASD and moderate language delays, it is ready for wider application. In this study, the DI-LL program will be given by trained behavior therapists.

Study Design: This will be a 24-week study comparing DI-LL to continued treatment as usual. Most children with ASD and moderate language delays receive speech therapy in school and some may receive speech therapy outside school as well. Children will be able to continue current treatments during the study. To be eligible, children have to be between age 5 years and 7 years 11 months and have moderate language delay based on a standardized test. We will enroll 100 children in the study. Fifty children will be randomly assigned to DI-LL and 50 children to continued treatment as usual. Random assignment is a fair way of testing whether DI-LL is better than treatment as usual for children with ASD and moderate language delays.

Measuring Progress: We will measure progress with two commonly used language tests, parent interviews and by direct observation of spoken language in semi-scripted, parent-child interaction in the clinic. All measures of progress will be carried out by trained clinicians who will not know if the child is in DI-LL or in treatment as usual. At the end of the study, we will use standard statistical tests to compare the progress on the study measures in the group that received DI-LL to those who received treatment as usual. NOTE: Children originally randomized to treatment as usual who do not show meaningful improvement will be offered DI-LL after Week 24.

Impact: We do not know if DI-LL works in children with ASD and moderate language delay. If the study shows that DI-LL is beneficial, it will be an important step. A major strength of DI-LL is that it can be delivered by a range of practitioners and could be delivered in a range of settings including underserved areas.