Over the last couple of decades, the numbers of people with autism has increased noticeably. In the United States, babies and toddlers are routinely tested for this disorder, which is mainly characterized by an inability to communicate. Louis Theroux travels to DLC Warren in New Jersey, an unusual school that proves a specialized approach really does pay off. He meets the pupils and learns about the way they perceive the world around them. But he also talks to their parents, to find out more about the huge impact it has had on their home life.