Interventions to address core symptoms for young children on the autism spectrum have a strong and growing evidence base. Adapting and delivering evidence-based interventions to infants and toddlers with a high likelihood for autism is a logical next step. This systematic review and meta-analysis summarize the association between infant and toddler interventions and developmental and family outcomes. Results indicate that these early interventions are effective for improving parent implementation of core strategies, yet the effects do not readily translate to child outcomes. However, key studies demonstrate conditional results that indicate that parent implementation is associated with child outcome. Implications for research and practice toward building adaptive interventions that respond to parent implementation and changing child characteristics are discussed.
Keywords: high likelihood for autism; intervention; meta-analysis; systematic review.