Examining the independent and combined effects of autistic and ADHD traits on multisensory integration

Multisensory integration differences have been reported in individuals with Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD), yet little is known about how these traits may jointly influence multisensory processing. Given the high comorbidity between ASD and ADHD, examining their individual and combined effects is critical for understanding sensory integration in neurodivergent populations. The present study examined associations between Autistic and ADHD traits and multisensory integration in a broad university sample of 92 young adults (62 females, M_age  = 18.29, age range = 17-24). Participants completed a speeded detection task to assess multisensory gain and self-report measures of Autistic and ADHD traits. Autistic and ADHD traits were not associated with accuracy gain. No evidence was found for an interactive or additive effect of co-occurring Autistic and ADHD traits on multisensory integration. These findings suggest that multisensory integration in young adults may be largely independent of Autistic and ADHD trait expression when perceptual sensitivity is controlled. This highlights the importance of accounting for individual sensory thresholds when studying multisensory processing in neurodivergent populations, and suggests that differences in multisensory integration may be more strongly influenced by diagnostic status or developmental stage than by trait variation alone.