A systematic review was conducted to identify effective intervention strategies for communication in individuals with Down syndrome. We updated and extended previous reviews by examining: (1) participant characteristics; (2) study characteristics; (3) characteristics of effective interventions (e.g., strategies and intensity); (4) whether interventions are tailored to the Down syndrome behavior phenotype; and (5) the effectiveness (i.e., percentage non-overlapping data and Cohen’s d) of interventions. Thirty-seven studies met inclusion criteria. The majority of studies used behaviour analytic strategies and produced moderate gains in communication targets. Few interventions were tailored to the needs of the Down syndrome behaviour phenotype. The results suggest that behaviour analytic strategies are a promising approach and future research should focus on replicating the effects of these interventions with greater methodological rigor
