Sensory Processing of Individuals with Autism Spectrum Disorder and an Intellectual Disability: A Systematic Review.

Background:

Autism Spectrum Disorders (ASD) and Intellectual Disabilities (ID) both coincide with atypical sensory processing. The severity of one of these disorders could have an impact on the other disorder regarding a number of outcomes. Little is known about the impact the combination of both conditions has on sensory processing. To date, we do not know to what extent the sensory processing of individuals with both ASD and ID differ from individuals with ASD or ID alone and what the impact will be on daily functioning.

Objectives:

The aims of this systematic review are 1) to investigate how individuals with both ASD and ID differ from individuals with ASD or ID alone in their sensory processing, and 2) to examine whether and how sensory processing problems are related to outcomes linked to sensory processing problems for individuals with ASD and/or ID.

Methods:

We searched three different databases: PubMed, PsycINFO, and Education Resources Information Center (ERIC), regarding papers published after 2010. For each database, a specific search strategy was developed. Search terms included key words and synonyms for the concepts: autism, intellectual disability, and sensory processing. We also searched in Online First, a website on which articles are presented that have not been published yet but will be published soon in peer-reviewed journals. Identified studies were first screened for eligibility for possible inclusion based on title and abstract. The next step was full text reading of the selected articles, systematic data-extraction and testing on quality of research. To answer the research questions, the outcomes of the three groups under study were compared: 1) ASD&ID, 2) ASD alone, and 3) ID alone.

Results:

The search yielded 800 studies which in particular covered descriptions of different sensory processing profiles for individuals with autism and outcomes such as stereotyped and repetitive behavior. Evidence on the sensory processing of the group of individuals with ASD and ID was very limited. We will be able to present full findings at the conference, regarding both research questions. For aim 1, an overview of the current state of knowledge of the sensory processing for each group will be given. If possible, a specification into different categories will be made. For aim 2, studies about the relationship between sensory processing problems and outcomes linked to sensory processing problems for individuals with ASD and/or ID will be shown.

Conclusions:

We will give an overview of the current state of evidence on the sensory processing of individuals with ASD and/or ID. We will also have insight into background and severity of sensory processing problems and differences between groups. Also, we will have gained insight into the outcomes linked to sensory processing problems for all three research groups. This review shows that evidence on the research group of individuals with ASD and ID is particularly limited. Study findings will help in gaining a better understanding of the sensory processing of individuals with ASD and/or ID, and may direct future research.