Internalising problems are prevalent amongst neurodevelopmental conditions and associated with a range of negative outcomes. Yet, the unique contributions of autistic and ADHD traits remain under-researched. Using the Comprehensive Autistic Trait Inventory (CATI), ADHD Self-Report Scale (ASRS), and the Depression Anxiety Stress Scales (DASS), this study aimed to quantify the relative contributions of autistic and ADHD traits to internalising problems. Adopting a traits-based approach in a general population sample 239 adults took part. Regression and dominance analysis indicated both autistic and ADHD traits predicted internalising problems, and that autistic traits were the stronger predictor. This is contrary to the other research which implied ADHD traits have the greatest bearing; however, this study used different measures and indicates that measures focussing on cognition may have overlooked the physical manifestations of internalising problems in individuals with higher autistic traits. Whilst camouflaging was touched upon, its impact requires further investigation.
Metcalfe et al. (Tue,) studied this question.