A School Psychologist Investigates Sensory Integration Therapies: Promise, Possibility, and the Art of Placebo By Steven R. Shaw, NCSP
Anyone who works with children with autism, learning disabilities, or mental retardation has observed the child who craves being held tightly, the child with high pain tolerance, the child with tactile defensiveness, the child who is clumsy, and the child who cannot tolerate tags on the inside of her shirt. Sensory integration (SI) dysfunction appears to be a productive explanation for these problems (American Occupational Therapy Association, 1997; Case-Smith & Bryon, 1999). Moreover, SI therapy seems a logical approach to addressing these issues.
Background of Sensory Integration Therapy
Sensory integration is a normal developmental process involving the ability of the central nervous system (CNS) to organize sensory feedback from the body and the environment in order to make successful adaptive responses (Ermer & Dunn, 1998). The basic tenets of SI are: 1) the CNS is plastic; 2) SI matures along a predictable developmental sequence; 3) SI therapy attempts to revisit and restructure the development of sensory integration in cases where the normal developmental progression has been disrupted; 4) SI therapy links an adaptive response to sensory input; and 5) children have an inner drive to integrate information (Bundy, Lane, Fisher, & Murray, 2002). Among the therapeutic techniques are deep brushing; swings for vestibular input; textures; bounce pads; scooter boards; weighted vests and other clothing; ramps; and generally increasing or decreasing sensory diet, depending on the needs of the child. When Jean Ayres (1979) first developed SI she proposed that, by revisiting the developmental process of integrating information from the senses into an organized whole through a carefully controlled sensory diet, learning disabilities and other developmental disabilities could be cured (Carte, Morrison, Sublett, Uemura, & Setrakian, 1984; Kranowitz, Szlut, Balzer-Martin, Haber & Sava, 2001).
Evidence Belies Appeal of SI
There is one small problem. The problem is that it does not work. There is no evidence that SI therapy is or has ever been an effective treatment for children with learning disabilities, autism, or any other developmental disability. This is not one of those common cases where there is not enough information upon which to effectively evaluate the treatment. In fact, there are plenty of quality outcome studies (41 as of this writing). There is no study that uses a quality research design (e.g., random assignment of subjects, matched control groups, consideration of the effects of maturation, evaluators blind to treatment condition) that finds SI therapy to be effective in reducing any problem behaviors or increasing any desired behaviors. There is plenty of evidence from which a verdict can be drawn. And the verdict is that, despite the intuitive appeal and glowing testimonials, SI therapy is not an effective treatment (Gresham, Beebe-Frankenburger, & MacMillan, 1999; Hoehn & Baumeister, 1994; Shaw, Powers, Abelkop, & Mullis, 2002).
Literature in a field can be compiled and integrated through a method called meta-analysis. All results are reduced to a metric called an effect size. Effect sizes are expressed in standard deviation units. The rule of thumb is that an effect size greater than .50 is large and an effect size of .20 to .50 is moderate. Effect sizes of less than .20 are rarely significant. Another common pattern is that poorly designed studies result in greater effect sizes than well-designed studies. That is the case with SI therapy. Several early studies that did not assign participants randomly found positive outcomes. Forty-one studies had random assignment of subjects, which is considered a minimum criterion for a quality design. Subjects include children with the following diagnoses (N refers to the number of studies considered): autism (N=8), learning disabilities (N=23), mental retardation (N=5), motor problems (N=3) and multiple developmental issues (N=2).
From all of these studies, each with multiple variables, 218 effect sizes were calculated. Of note is that there were no significant effect sizes for language improvement (-.08), behavior (.02) and sensory motor functions (-.10). There were small, but significant effects for motor skills (.24) and psychoeducational performance (.26). However, if only the studies that considered maturation factors are included (N=12), then the effect sizes for motor skills and psychoeducational performance are reduced to nearly zero (.03 and -.04, respectively; Shaw et al., 2002).
There simply is no evidence of the efficacy of SI therapy (Cummins, 1991). Many have tried. It certainly is possible that the studies lacked sufficient power to demonstrate effectiveness, dependent measures are not sufficiently sensitive to change, or that experimental designs may be biased against finding positive effects (Vargas & Camilli, 1999). These are important academic questions to be answered. However, for a procedure with no evidence of efficacy to be used on the public with claims of success, to charge money for these services, and to train practitioners in this model borders on unethical behavior. At least some evidence that SI procedures are “safe and effective,” to use Food and Drug Administration language, is required before moving a technique from theory and experimentation to the public.
The Placebo Effect of SI
If this is so, then why do so many therapists and parents swear by the effectiveness of SI therapy? In a word: placebo. Placebo is a powerful tool used in many professions. If someone believes that a therapy works and invests personal energy into making a therapy work, then to some degree it will work. In SI therapy a skilled professional is spending one-on-one time with a child, coaching parents on how to interact with their child, supplying answers to parents, and giving parents hope (Ottenbacher, 1982). These are fabulous and valuable activities. Parents are empowered. Parents become hopeful and involved. However, these activities have nothing to do with SI therapy. A professional could provide the same positive messages by giving the child a massage or playing checkers with a child and there would be the perception of positive outcomes. Placebo is neither a bad thing nor something to be ignored. There is an estimate that 30% of physician treatment effectiveness is due to placebo (Roberts, Lauriello, Geppert, & Keith, 2001). Certainly the same is probably true of psychological counseling (Roberts, et al., 2001). I rarely dismiss SI as a treatment option because there is likely to be some good derived from the family working with these skilled professionals. I will only argue against SI when the diagnosis of SI dysfunction and subsequent treatments interfere with a more appropriate diagnosis with a potential to result in an effective treatment plan. Perhaps this is a wrong approach. If parents, Medicaid, or insurance companies are paying 60 to 80 dollars per hour of therapy, then they should be ensured that the child is receiving an effective treatment rather than a placebo.
An interesting phenomena is noted on the popular website Amazon.com. A popular part of this website is that people who have read books submit short reviews. These reviews are posted along with other information about the book. Customers then write in to say how helpful is a given review. Reviews of the popular book, The Out-of-Sync Child (Kranowitz & Silver, 1998), that were positive, glowing, and unquestioning were usually considered to be helpful (19 of 20 comments). The one review that questioned the book’s major premises was universally reported to not be helpful at all (0 of 4 comments). People want firm and intuitively appealing answers, identification of causes of the problems, and guaranteed cures. The general public values certainty. Scientific support is irrelevant. The probabilistic approach of science is not as satisfying to desperate parents as unquestioned conviction, certainty of conclusions and declarations of “fact.”
Close to Psuedoscience?
To a scientist-practitioner there are several extremely disturbing aspects of SI. There are several aspects of SI that are dangerously close to the criteria used to define pseudoscience (Gardner, 1982). Among these criteria are: a) Reliance on subjective validation (i.e., failing to consider maturity, errors in initial diagnoses and the effects other valid treatment regimens in cases where children improve); b) nearly exclusive reliance on anecdotes, rumor, common sense and eyewitness testimony to support a treatment validity; c) an indifference to facts (i.e., despite advances in developmental cognitive neuroscience and a large body of research on SI, there have been no major changes in theory of SI since Jean Ayres’s 1979 book, Sensory Integration and the Child); d) beginning with a spectacular and emotionally appealing hypothesis and only acknowledging supporting items while ignoring all contrary evidence; e) deliberately creating mysteries and mysterious new constructs (i.e., SI theorists invented the concept of “near senses” and refers to mysterious plasticity of the CNS without explanation of how SI uses neural plasticity toward a restructuring of brain structure); f) the literature is aimed at the general public rather than the academic or clinical community; and g) convinces people by appeals to hope and faith in cases where the scientific and clinical community has no scientifically accepted answers. Moreover, the original SI therapy was developed for use for children with learning disabilities. This application of SI therapy is nearly universally discredited (see DiMatties and Quirk  for an exception). Now SI therapy is being applied to children with autism, developmental dyspraxia, mental retardation, nonverbal learning disabilities and children with general motor clumsiness and environmental sensitivities. SI proponents may eventually find or create a disorder that SI therapies effectively treat. At this point, the search continues.
Ties to Psychomotor Patterning
There are many similarities between SI and psychomotor patterning that are also disturbing. Psychomotor patterning,
popularized by Doman and Delacato, is a method that posits the child has not effectively acquired neurodevelopmental and evolutionary motor patterns (i.e., the assumption that ontogeny recapitulates phylogeny is given great emphasis in this model). A diet of sensory input, appropriate nutrition, breathing exercises and series of patterned motor movements are proposed to cure learning disabilities, mental retardation, brain injury and autism. The diet of sensory input and motor movements are quite similar to those now used in SI. Psychomotor patterning has been dismissed on two occasions by the American Academy of Pediatrics (1982; 1999) as completely ineffective. Psychomotor patterning is also featured on the website, www.quackwatch.org (Novella, 2001).
While Awaiting Research EvidenceÅ .
Despite this harsh criticism, SI theorists and practitioners may be close to something important. I strongly encourage continued research in this area. However, the general public should not be Guinea pigs. Nor should resources be taken from effective treatments to go towards an unproved treatment. I hope that when new and improved SI models are proven safe and effective, they will dramatically improve the lives of children and their families. When there is evidence of SI as a safe and effective treatment, I promise to publicize such positive findings as vigorously as I have pointed out its current shortcomings.
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Hoehn, T. P., & Baumeister, A. A. (1994). A critique of the application of sensory integration therapy to children with learning disabilities. Journal of Learning Disabilities, 27, 338-350.
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Kranowitz, C. S., Szlut, S., Balzer-Martin, L., Haber, E., & Sava, D. I. (2001). Answers to questions teachers ask about sensory integration. Las Vegas, NV: Sensory Resources.
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Roberts, L. W., Lauriello, J., Geppert, C., & Keith, S. J. (2001). Placebos and paradoxes in psychiatric research: An ethics perspective. Biological Psychiatry, 49, 887-893.
Shaw, S. R., Powers, N. R., Abelkop, S., & Mullis, J. (2002, February). Sensory integration therapy: Panacea, placebo, or poison? Paper presented to the annual convention of the National Association of School Psychologists. Chicago, IL.
Vargas, S., & Camilli, G. (1999). A meta-analysis of research on sensory integration treatment. The American Journal of Occupational Therapy, 53, 189-198.
Steven R. Shaw, Ph.D., NCSP, is a CommuniquÃ© Contributing Editor and the lead school psychologist at The Children’s Hospital, Greenville, SC and Associate Professor of Pediatrics, Medical University of South Carolina. Parts of this paper
were presented at the 2002 Annual NASP Convention and appeared in The Tennessee School Psychologist. He can be
reached for comments and hate mail at email@example.com.