Autistic and ADHD Traits and their Relationships with Atypical Sensory Processing and Anxiety

Autism and attention deficit hyperactivity disorder (ADHD) frequently co-occur and show a positive correlation when examined as traits in the general population. Both are associated with anxiety, and Atypical Sensory Processing (ASP) may play a role in this relationship. A cross-sectional design was used to examine ASP as a mediator between autistic / ADHD traits and anxiety and explore the role of ASP in their shared variance. A total of 224 adults from the general population completed self-report surveys of ADHD traits, autistic traits, ASP, and anxiety. All measures correlated positively, and ASP was a partial mediator between autistic traits and anxiety and between ADHD traits and anxiety. In a partial correlation, ASP accounted for the majority of the shared variance between ADHD and autistic traits. Mediation of anxiety via ASP appeared to stem from the shared variance between ADHD and autism but not their unique variance. These results highlight the importance of considering ASP as a source of anxiety for those with higher autistic and ADHD traits. ASP is suggested as a transdiagnostic factor that may help explain the high co-occurrence of ADHD and autism. Areas for further research are discussed.