Previous studies have targeted skills important to language development, but many only looked at small groups of children or infrequent treatment sessions, Kasari notes. Understanding what makes a treatment successful or not is vital. "We need to distill down the active ingredients in early intervention," she says, "then take these elements and match them to programs."
This kind of long-term follow-up is rare. "The study is important in terms of raising expectations of what can be accomplished, and in raising awareness of how much work it takes," says Sally J. Rogers, a psychiatry professor with the MIND Institute at the University of California, Davis. Rogers, who was not involved in the research, emphasized that because the subjects were very young, the study builds on evidence indicating that the earlier the intervention the better—and children even younger than the toddlers in the original study could benefit. This has important pubic policy implications, she says, because there is little funding for children younger than three.
Finding a one-size-fits-all approach to helping autistic kids talk may be tricky, however: Autism affects each child differently, Rogers observes, and even the best interventions will have varied outcomes.