Network Analysis of ADHD and Autism Spectrum Disorder Symptoms in Clinic-Referred Adolescents

Background Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) often co-occur and share overlapping cognitive, emotional, and social characteristics, but the symptom-level processes underlying this comorbidity remain unclear. Method Using regularised partial correlation network analysis (EBIC-glasso), this study examined the structure, centrality, and connectivity of DSM-5-TR ADHD and ASD symptoms in a clinic-referred sample of 942 adolescents (aged 11–17), based on parent ratings. Results The network showed clear separation between ADHD and ASD symptom clusters, with stronger internal connections among ADHD symptoms and weaker cross-condition associations. Hyperactive–impulsive symptoms demonstrated the highest centrality overall. The most central symptoms were “Has a strange way of relating to other people” (ASD1), “Has trouble sitting still or staying in my seat” (ADHD11), and “Distracted even when someone is speaking to them” (ADHD3). The strongest bridge symptoms linking the ADHD and ASD symptom clusters were “Gets frustrated when I have to wait my turn to do things” (ADHD17), “Is unaware of, or takes no interest in, other people’s feelings” (ASD4), and “Gets fixated on things” (ASD12). Conclusions Overall, results suggest that co-occurrence may be shaped by specific highly influential symptoms, particularly hyperactivity-impulsivity and select social-emotional or restrictive/repetitive features, highlighting the value of targeting central and bridging symptoms in assessment and intervention.