Sensory integration refers to the process by which the brain organizes and interprets external stimuli such as touch, movement, body awareness, sight, sound and gravity. It has been postulated that certain behavioral and emotional problems result from the malfunctioning of this process. Sensory integration therapy (SIT) is a type of treatment usually performed by occupational therapists or physical therapists who provide various sensory stimulation to the patient, often in combination with and within the context of purposeful muscle activities, to improve how the brain processes and organizes sensory information. This type of therapy requires activities that consist of full body movements employing different kinds of equipment such as textured mitts, carpet squares, scooter boards, ramps, swings, and bounce pads. It is believed that SIT does not teach higher level skills, but enhances the sensory processing abilities of the subject to acquire them.
Although the use of SIT as a treatment for children with learning disabilities and other behavioral disorders (e.g., autism, attention-deficit disorder, fragile X syndrome, and developmental delay) has been quite popular, there is widespread skepticism regarding its effectiveness. Kaplan et al (1993) stated that SIT is not more effective than other, more conventional methods of treatment for children with learning disabilities. Hoehn and Baumeister (1994) reported that SIT is not only an unproven, but also an ineffective, primary or adjunctive remedial treatment for children with learning disabilities and other disorders.
Tharpe (1996) stated that “Although anecdotal reports and testimonials of positive treatment outcomes abound, there remains a dearth of empirical studies designed to scrutinize the claims made by proponents of auditory integration therapy. Until such time that auditory integration therapy technology meets the standards of scientific efficacy, it is best considered to be an experimental treatment....” Furthermore, the American Speech-Language-Hearing Association declared that auditory integration training is an experimental procedure because it has not yet satisfied standards for effectiveness that would justify the inclusion of this method as a mainstream treatment for a variety of communication, behavioral, emotional, and learning disorders. The American Academy of Pediatrics (1998) has suggested that auditory integration training should be used for research purposes only.
An assessment of auditory integration therapy (AIT) for autism by the Wessex Institute concluded that trials have produced conflicting results, and it is uncertain whether AIT is any more effective than placebo (Best and Milne, 1997). A systematic evidence review by Cullen et al (1999) concluded: "Previous claims for the benefits of AIT in reduction of problem behaviors and increases in IQ and adaptive/social skills were not supported by the results. AIT may divert parents' and service providers' resources from better-validated interventions".
An assessment conducted by the National Initiative for Autism (UK) (2003) concluded: "Auditory integration therapy has also recently been subject to careful analysis, and again the results indicate that the effects are no greater than for placebo conditions [Mudford et al, 2000; Dawson and Watling, 2000]."
A meta-analysis of research on sensory integration treatment (Vargas and Camilli, 1999) concluded that more recent studies do not show overall positive effects from sensory or auditory integration therapies.
An assessment conducted by the National Initiative for Autism (UK) (2003) stated: "Experimental data in support of a variety of other treatments, such as Facilitated Communication, auditory or sensory integration programmes, psychoanalytically based interventions or teaching methods such as the Son Rise programme (Option), Walden or Daily Life Therapy (Higashi) did not exist".
An assessment conducted by Hender (2001) for the Centre for Clinical Effectiveness (Monash University) identified no randomized controlled clinical studies of SIT for attention-deficit hyperactivity disorder, and identified only 1 study (Werry et al, 1990), a comparative study with concurrent controls. Hender (2001) noted the sources of bias that limit reaching definitive conclusions about the effectiveness of SIT for attention-deficit hyperactivity disorder from this single study.
An assessment conducted by the National Academy of Sciences (NAS) (2001) concluded that there is insufficient evidence of the effectiveness of SIT for autism. The NAS report states that “[t]here is a paucity of research concerning sensory integration treatments in autism…. These interventions have also not yet been supported by empirical studies.” In addition, the American Academy of Pediatrics (AAP, 2001) stated that research data supporting the effectiveness of SIT in managing autistic children is scant.
The NAS (2001) concluded that there is insufficient evidence of the effectiveness of AIT in autism. The NAS concluded that “auditory integration therapy has received more balanced investigation than has any other sensory approach to intervention, but in general studies have not supported either its theoretical basis or the specificity of its effectiveness.”
Tochel (2003) performed a structured evidence review of SIT and AIT for the Wessex Institute. Regarding SIT, the assessment concluded that “[w]e have found insufficient evidence about the clinical effects of sensory integration therapy in children with autistic spectrum disorders.” Regarding AIT, the report found “[w]eak evidence from limited research suggests that AIT is unlikely to be more effective than unprocessed music in children with autistic spectrum disorders, although both AIT and unprocessed music may be associated with similar improvement in some scores from baseline. However, the clinical importance of these changes is unclear.”
Sinha et al (2004) reported on the results of a structured evidence review for the Cochrane Collaboration of AIT for autism. The investigators reported that there is “[n]o clear evidence yet for auditory integration therapy's effect on autism.” The investigators explained that “[s]ix relatively small studies met the inclusion criteria for AIT. These largely measured different outcomes and reported mixed results. Suggestion of benefit in two outcomes requires corroboration by further research using well-designed trials with long-term follow-up.” The review also concluded that more research is needed to inform parents', carers' and practitioners' decision making about this therapy for individuals with autism spectrum disorders (ASDs).
In a systematic review, Sinha and colleagues (2006) evaluated the effectiveness of AIT and other sound therapies in people (adults or children) with ASDs. A total of 6 randomized controlled trials (RCTs) of AIT, including 1 cross-over study, were identified, with a total of 171 participants aged 3 to 39 years; 17 different outcome measures were used, with only 2 outcome measures used by 3 or more studies. Meta-analysis was not possible owing to very high heterogeneity or presentation of data in unusable forms. Three studies did not show any benefit of AIT over control conditions; 3 studies reported improvements at 3 months in the AIT group for total mean scores of the Aberrant Behavior Checklist (ABC), which is of questionable validity. Of these, 1 study also reported improvements at 3 months in the AIT group for ABC subgroup scores. No significant adverse effects of AIT were reported. The authors concluded that currently there is insufficient evidence to support the use of AIT for individuals with ASDs.
Parham et al (2007) evaluated the validity of sensory integration outcomes research in relation to fidelity (faithfulness of intervention to underlying therapeutic principles). These investigators identified core sensory integration intervention elements through expert review and nominal group process. Elements were classified into structural (e.g., equipment used, therapist training) and therapeutic process categories. They analyzed 34 sensory integration intervention studies for consistency of intervention descriptions with these elements. They reported that most studies described structural elements related to therapeutic equipment and interveners' profession. Of the 10 process elements, only 1 (presentation of sensory opportunities) was addressed in all studies. Most studies described fewer than half of the process elements. Intervention descriptions in 35 % of the studies were inconsistent with one process element, therapist-child collaboration. The authors concluded that the validity of sensory integration outcomes studies is threatened by weak fidelity in regard to therapeutic process. They stated that inferences regarding sensory integration effectiveness can not be drawn with confidence until fidelity is adequately addressed in outcomes research.
A systematic evidence review prepared for BMJ Clinical Evidence judged auditory integration training and sensory integration training to be of "unknown effectiveness" for the treatment of autism (Parr, 2006). The assessment stated that they found no clinically important results about the effects of sensory integration training or auditory integration training on autism in children.
Fazlioglu and Baran (2008) examined the effect of a SIT program on sensory problems of children with autism (according to DSM-IV criteria). Subjects were separated into 2 groups, each comprising 15 children aged 7 to 11 years. They were assessed initially on a checklist, Sensory Evaluation Form for Children with Autism, developed to evaluate sensory characteristics of children with autism, and at the end of the study, participants were assessed again on the checklist. Statistically significant differences between groups indicated that the sensory integration therapy program positively affected treated children. It is unclear whether these effects are clinically significant. The findings of this study need to be validated by more research.
Hess et al (2008) noted that the Autism Treatment Survey was developed to identify strategies used in education of children with ASD in Georgia. Respondents of the web-based survey included a representative sample of 185 teachers across the state, reporting on 226 children with ASD in grades pre-school to 12th. The top 5 strategies being used in Georgia (Gentle Teaching, sensory integration, cognitive behavioral modification, assistive technology, and Social Stories) are recognized as lacking a scientific basis for implementation. Analysis revealed the choice of strategies varied by grade level and classroom type (e.g., general education, special education). Results highlight clear implications for pre-service and in-service educator training, and the need for continued research to document evidence-based strategy use in public schools for students with ASD.
In a pilot study, Miller et al (2007a) examined the effectiveness of occupational therapy using a sensory integrative approach (OT-SI) for children who had sensory modulation disorders (SMDs). This study evaluated the effectiveness of 3 treatment groups. In addition, sample size estimates for a large scale, multi-site randomized controlled trial were calculated. A total of 24 children with SMD were randomly assigned to one of three treatment conditions; (i) OT-SI, (ii) activity protocol, and (iii) no treatment. Pre-test and post-test measures of behavior, sensory and adaptive functioning, and physiology were administered. The OT-SI group, compared to the other 2 groups, made significant gains on goal attainment scaling and on the Attention subtest and the Cognitive/Social composite of the Leiter International Performance Scale-Revised. Compared to the control groups, OT-SI improvement trends on the Short Sensory Profile, Child Behavior Checklist, and electrodermal reactivity were in the hypothesized direction. The authors concluded that the findings of this pilot study suggested that OT-SI may be effective in ameliorating difficulties of children with SMD. They stated that more studies are needed to answer the plethora of questions relating understanding whether OT-SI is an effective intervention, for whom, and under what conditions.
Miller et al (2007b) prepared for a RCT of the effectiveness of OT-SI for children who have sensory processing disorders (SPD). A one-group pre-test, post-test design with 30 children was completed with a subset of children with SPD, those with SMD. Lessons learned relate to (a) identifying a homogeneous sample with quantifiable inclusion criteria, (b) developing an intervention manual for study replication and a fidelity to treatment measure, (c) determining which outcomes are sensitive to change and relate to parents' priorities, and (d) clarifying rigorous methodologies (e.g., blinded examiners, randomization, power). The authors concluded that a comprehensive program of research is needed, including multiple pilot studies to develop enough knowledge that high-quality effectiveness research in occupational therapy can be completed. Previous effectiveness studies in OT-SI have been single projects not based on a unified long-term program of research.
In a review on autism, Levy and colleagues (2009) stated that popular biologically based treatments include anti-infectives, chelation medications, gastrointestinal medications, hyperbaric oxygen therapy, and intravenous immunoglobulins. Non-biologically based treatments include AIT, chiropractic therapy, cranio-sacral manipulation, facilitated communication, interactive metronome, and transcranial stimulation. However, few studies have addressed the safety and effectiveness of most of these treatments.
In a systematic review on novel and emerging treatments for ASD, Rossignol (2009) stated that currently, only 1 medication (risperidone) is approved by the Food and Drug Administration for the treatment of ASD. The use of novel, unconventional, and off-label treatments for ASD is common, with up to 74 % of children with ASD using these treatments; however, treating physicians are often unaware of this usage. The author performed a systematic literature search of electronic scientific databases was performed to identify studies of novel and emerging treatments for ASD, including nutritional supplements, diets, medications, and non-biological treatments. A grade of recommendation ("Grade") was then assigned to each treatment using a validated evidence-based guideline as outlined in this review: Grade A: Supported by at least 2 prospective RCTs or 1 systematic review; Grade B: Supported by at least 1 prospective RCT or 2 non-RCTs; Grade C: Supported by at least 1 non-RCT or 2 case series; and Grade D: Troublingly inconsistent or inconclusive studies or studies reporting no improvements. Potential adverse effects for each treatment were also reviewed. Grade A treatments for ASD include melatonin, acetylcholinesterase inhibitors, naltrexone, and music therapy. Grade B treatments include carnitine, tetrahydrobiopterin, vitamin C, alpha-2 adrenergic agonists, hyperbaric oxygen treatment, immunomodulation and anti-inflammatory treatments, oxytocin, and vision therapy. Grade C treatments for ASD include carnosine, multi-vitamin/mineral complex, piracetam, polyunsaturated fatty acids, vitamin B6/magnesium, elimination diets, chelation, cyproheptadine, famotidine, glutamate antagonists, acupuncture, AIT, massage, and neurofeedback. The author concluded that the reviewed treatments for ASD are commonly used, and some are supported by prospective RCTs. Promising treatments include melatonin, anti-oxidants, acetylcholinesterase inhibitors, naltrexone, and music therapy. All of the reviewed treatments are currently considered off-label for ASD and some have adverse effects. The author stated that further studies exploring these treatments are needed.
In a systematic review, May-Benson and colleagues (2010) evaluated the literature on the effectiveness of SIT on the ability of children with difficulty processing and integrating sensory information to engage in desired occupations and applied these findings to occupational therapy practice. Results suggested the SIT may result in positive outcomes in sensori-motor skills and motor planning; socialization, attention, and behavioral regulation; reading-related skills; participation in active play; and achievement of individualized goals. Gross motor skills, self-esteem, and reading gains may be sustained from 3 months to 2 years. Findings may be limited by type II error because of small sample sizes, variable intervention dosage, lack of fidelity to intervention, and selection of outcomes that may not be meaningful to clients and families or may not change with amount of treatment provided. The authors stated that replication of findings with methodologically and theoretically sound studies is needed to support current findings.
In a Cochrane review, Sinha and colleagues (2011) examined the effectiveness of AIT or other methods of sound therapy in individuals with ASDs. For this update, these investigators searched the following databases in September 2010: CENTRAL (2010, Issue 2), MEDLINE (1950 to September week 2, 2010), EMBASE (1980 to Week 38, 2010), CINAHL (1937 to current), PsycINFO (1887 to current), ERIC (1966 to current), LILACS (September 2010) and the reference lists of published papers. One new study was found for inclusion. Randomized controlled trials involving adults or children with ASDs were included in this analysis. Treatment was AIT or other sound therapies involving listening to music modified by filtering and modulation. Control groups could involve no treatment, a waiting list, usual therapy or a placebo equivalent. The outcomes were changes in core and associated features of ASDs, auditory processing, quality of life and adverse events. Two independent review authors performed data extraction. All outcome data in the included papers were continuous. The authors calculated point estimates and standard errors from t-test scores and post-intervention means. Meta-analysis was inappropriate for the available data. They identified 6 RCTs of AIT and 1 of Tomatis therapy, involving a total of 182 individuals aged 3 to 39 years. Two were cross-over trials; 5 trials had fewer than 20 participants. Allocation concealment was inadequate for all studies. Twenty different outcome measures were used and only 2 outcomes were used by 3 or more studies. Meta-analysis was not possible due to very high heterogeneity or the presentation of data in unusable forms. Three studies (Bettison 1996; Zollweg 1997; Mudford 2000) did not demonstrate any benefit of AIT over control conditions; 3 studies (Veale 1993; Rimland 1995; Edelson 1999) reported improvements at 3 months for the AIT group based on the Aberrant Behaviour Checklist, but they used a total score rather than subgroup scores, which is of questionable validity, and Veale's results did not reach statistical significance. Rimland (1995) also reported improvements at 3 months in the AIT group for the Aberrant Behavior Checklist subgroup scores. The study addressing Tomatis therapy (Corbett 2008) described an improvement in language with no difference between treatment and control conditions and did not report on the behavioral outcomes that were used in the AIT trials. The authors concluded that there is no evidence that AIT or other sound therapies are effective as treatments for ASDs. As synthesis of existing data has been limited by the disparate outcome measures used between studies, there is insufficient evidence to prove that this treatment is not effective. However, of the 7 studies including 182 participants that have been reported to date, only 2 (with an author in common), involving a total of 35 participants, reported statistically significant improvements in the AIT group and for only 2 outcome measures (Aberrant Behavior Checklist and Fisher's Auditory Problems Checklist). As such, there is no evidence to support the use of AIT at this time.
The AAP Committee on Children with Disabilities has stated that the scientific legitimacy of SIT has not been established for children with motor disabilities. The AAP also stated that successful therapy programs are individually tailored to meet the child’s functional needs and should be comprehensive, coordinated, and integrated with educational and medical treatment plans, with consideration of the needs of parents and siblings. This can be facilitated by primary care pediatricians and tertiary care centers working cooperatively to provide care coordination in the context of a medical home (AAP, 2004). A statement of re-affirmation for this policy was published on September 1, 2007.
The AAP Council on Children with Disabilities published guidelines for the management of children with ASDs. Regarding SIT, the guidelines stated that SIT is used alone or as part of a broader program of occupational therapy for children with ASDs. Unusual sensory responses are common in children with ASDs, but there is not good evidence that these symptoms differentiate ASDs from other developmental disorders, and the effectiveness of SIT has not been demonstrated objectively. Available studies are plagued by methodological limitations, but proponents of SIT noted that higher-quality SI research is forthcoming (Myers, et al, 2007).
The American Academy of Audiology’s position statement on auditory integration training (AAA, 2010) stated that auditory integration training (by any name) is investigational. The AAA believes that prospective, systematic research of this technique is needed to determine its effectiveness.
The American Academy of Pediatrics’ position statement on “Sensory integration therapies for children with developmental and behavioral disorders” (2012) stated that “Sensory-based therapies are increasingly used by occupational therapists and sometimes by other types of therapists in treatment of children with developmental and behavioral disorders. Sensory-based therapies involve activities that are believed to organize the sensory system by providing vestibular, proprioceptive, auditory, and tactile inputs. Brushes, swings, balls, and other specially designed therapeutic or recreational equipment are used to provide these inputs. However, it is unclear whether children who present with sensory-based problems have an actual "disorder" of the sensory pathways of the brain or whether these deficits are characteristics associated with other developmental and behavioral disorders. Because there is no universally accepted framework for diagnosis, sensory processing disorder generally should not be diagnosed. Other developmental and behavioral disorders must always be considered, and a thorough evaluation should be completed. Difficulty tolerating or processing sensory information is a characteristic that may be seen in many developmental behavioral disorders, including autism spectrum disorders, attention-deficit/hyperactivity disorder, developmental coordination disorders, and childhood anxiety disorders. Occupational therapy with the use of sensory-based therapies may be acceptable as one of the components of a comprehensive treatment plan. However, parents should be informed that the amount of research regarding the effectiveness of sensory integration therapy is limited and inconclusive”.