Third time's the charm or three strikes you're out? An updated review of the efficacy of dolphin-assisted therapy for autism and developmental disabilities.

CONTEXT: Dolphin-assisted therapy (DAT) is a popular form of animal-assisted therapy for autism spectrum disorders and other psychological conditions. OBJECTIVE: In this review, our third, we analyze the most recent DAT studies in terms of construct and internal validity criteria to determine if there is empirical support for DAT. METHOD: To ensure a systematic review, we searched for peer-reviewed studies on DAT by submitting relevant search terms to Google Scholar from 2007 to 2020, conducted a further search of all DAT papers in several peer-reviewed journals, and reviewed reference sections of DAT articles to ensure a thorough review of the literature between 2007 and the present. RESULTS: The DAT literature continues to be marked by several weaknesses in both internal and construct validity that preclude confident inferences regarding the intervention's efficacy. CONCLUSION: There is still insufficient evidence that DAT has therapeutic value.