Developmental therapies are based on an understanding of how all children develop and learn, and on the idea that the right kinds of effective intervention can support children’s progress along developmental pathways and stages.  They are grounded in the work of cognitive development research pioneers, Piaget (1896 – 1980) and Vygotsky (1896 -1934).

With this foundation drawn from child development, the research base on children with autism is accumulating:

• Use of a parent‐mediated model for ASD (Wong C, Odom S, Hume K, Cox, et al, 2013)

• Meets the National Research Centers standards for intensive early intervention (2001)

• Incorporates Greenspan and Weider’s D.I.R. (Developmental, Individual‐differences, Relationship‐based) theoretical framework (1997); RDI’s developmental stages are similar.

This research is one factor that led British Columbia to recognize DIR/Floortime and RDI as therapies eligible for funding.


Over the last few years, research indicating the effectiveness of DIR/Floortime has been accumulating.

PLAY Project (2014)

The PLAY Project recently completed a three‐year multi‐site randomized controlled trial which showed improvements in both parent‐child interaction and autism symptomatology.

This large scale study focused on the impact of our autism intervention with a parent-implemented play and relationship focused program.

Significant improvements in:

  • caregiver/parent and child interaction
  • social interaction of children with autism
  • social-emotional development of children with autism
  • autism symptomatology

Secondary outcomes:

  • Improved parent stress and depression; and
  • PLAY Project consultant fidelity.  In other words, they were true to the PLAY Project model and delivered it as trained.
MEHRI (2011)

Dr. Stuart Shanker of the Milton and Ethel Harris Research Initiative of York University (Toronto) completed a fairly large study.  “Learning through Social Interaction in Children with Autism” was published in Autism: The International Journal of Research and Practice. This study showed that an adapted version of DIR greatly increased the children’s capacity to share and initiate joint attention and reciprocal interaction with their parents, and to develop important functional language skills.

  • Casenhiser D, Shanker SG, Stieben J. (2011) Learning Through Social Interactions in Children with Autism: Preliminary Data from a Social-Communications-Based Intervention. Autism 26 Sept: 1-22

CBC News reported on this study in April, 2012.

An excellent article by Diane Cullinane explains what to look for in good research, and the studies that support developmental approaches like DIR/Floortime.  You can read it here: Evidence Base for DIR 2020.


Autism Severity and Parent-Child Interaction (2015)

The aim of this study was to examine the relations between severity of children’s autism and qualities of parent-child interaction.  Autism severity and the quality of parent-child interactions were assessed at two points when families were engaged in RDI.  Not only was there a correlation between the two at the beginning, but ratings on each of these variables changed over the course of treatment, and there was evidence that improvement was specifically related to the quality of parent-child interaction.

Amy Leventhal and Deborah Berrang have compiled a summary of research supporting Research Development Intervention (2011).

The RDI Connect website maintains a list of research studies.


Hanen is an educational organization focused on communication and literacy for young children.  They have created and made accessible developmental programs including books, DVDs, and training materials for parents (More Than Words and Talkability are specifically for children with autism).  They have compiled their own research summary, including both in-house studies and outside sources.

Emerging research strongly suggests that child centered, relationship based intervention is very effective in helping young children with autistic spectrum disorders gain language and social skills.

A lengthy list of studies supporting the use of developmental therapies is on the ICDL website: click here to view it.

For those who want to know more, we recommend a look at the article by Barry Prizant from Autism Spectrum Quarterly (2009), Is ABA the Only Way?  It provides some perspective in understanding research and the conclusions that can be drawn from it.

Another good resource is Jonathan Alderson’s Challenging the Myths of Autism (2011).  One chapter in particular examines the issue of research.  We have an interview with the author posted here.

Updated September 2015