Sensory Atypicalities in Individuals with Co-occurring Autism Spectrum Disorder and Attention Deficit/Hyperactivity Disorder: A Scoping Review Protocol

Abstract* Sensory atypicalities are recognized as a core feature of autism spectrum disorder (ASD) and are associated with a wide range of functional outcomes. Attention-deficit/hyperactivity disorder (ADHD) frequently co-occurs with ASD and may influence sensory experiences and sensory information processing through attentional and inhibitory mechanisms. Although an increasing number of studies have examined sensory atypicalities in co-occurring ASD and ADHD (ASD + ADHD), the evidence remains fragmented because of variability in the sensory modalities, constructs, and assessment methods employed. A scoping review is needed to map the extent and nature of the evidence on atypical sensory experiences and sensory information processing in individuals with ASD + ADHD. The review aims to clarify the contribution of ADHD comorbidity to sensory heterogeneity within ASD and identify priorities for future research. Specifically, it will examine the sensory modalities and constructs assessed, the assessment methods used, characteristics of sensory functioning, as well as associations with a wide range of outcomes. The review will include peer-reviewed primary studies published in English from 2013 onward that include individuals with ASD + ADHD and compare them with individuals with ASD. To clarify the contribution of ADHD comorbidity, studies that compare individuals with ASD and those with ADHD will also be reviewed. Eligible studies must examine sensory experiences or sensory information processing in at least one sensory modality. MEDLINE, Web of Science, and PsycINFO will be searched. Reference lists of included studies and relevant review articles will also be screened. Two reviewers will independently screen titles, abstracts, and full texts. Any disagreements will be resolved through discussion, and if consensus cannot be reached, a third reviewer will be consulted. Data will be charted using a standardized Excel-based form and summarized descriptively using tables, figures, and narrative synthesis.