Meta-analysis of naturalistic developmental behavioral interventions for young children with autism spectrum disorder.

Naturalistic developmental behavioral intervention is an emerging class of interventions for young children with autism spectrum disorder. The present article is a meta-analysis of outcomes of group-design studies (n = 27) testing interventions using naturalistic developmental behavioral intervention strategies. Small, significant positive effects of naturalistic developmental behavioral intervention were found for expressive language (g = 0.32), reduction in symptoms of autism spectrum disorder (g = -0.38), and play skills (g = 0.23). Larger effects were found for social engagement (g = 0.65) and overall cognitive development (g = 0.48). A marginal effect was found for joint attention (g = 0.14) and receptive language (g = 0.28). For joint attention, improvement was moderated by hours of professional involvement. Evidence of publication and reporting bias was present for language outcomes. This meta-analysis grows the evidence base for naturalistic developmental behavioral interventions, particularly in the key areas of social engagement and cognition.