Adverse childhood experiences and neurodevelopmental disorder traits: A nationwide cross‐sectional study

Abstract Aim In this study, we aimed to examine the associations between adverse childhood experience (ACE) exposure, adult autism spectrum disorder (ASD), and attention‐deficit/hyperactivity disorder (ADHD) traits in a nationwide sample, and assess links with specific symptom subdomains. Methods We conducted a cross‐sectional analysis using 2024 data from the Japan “Society and New Tobacco” Internet Survey. Adults ( N = 29,268; ≥18 years) completed self‐reports including the 10‐item ACE questionnaire (categorized: 0, 1, 2, 3, or ≥4 ACEs), Autism‐Spectrum Quotient short form, and Adult ADHD Self‐Report Scale. Logistic regression models assessed associations between ACEs and positive ASD (score ≥ 7) and ADHD (score ≥ 4) screens, adjusting for demographics, health, mental distress (K6), and alcohol use. Results Among respondents, 4.9% reported experiencing ≥4 ACEs. Positive screening rates were 11.9% for ASD traits and 7.7% for ADHD traits. ASD traits were only associated with high ACE exposure (≥4 ACEs: odds ratio [OR] 1.29, 95% confidence intervals [CIs] 1.11–1.49). ADHD traits showed a dose–response relationship starting at 1 ACE (OR 1.15, 95% CI 1.00–1.31), and increased with greater exposure (≥4 ACEs: OR 1.70, 95% CI 1.45–1.98). High exposure was linked to specific ASD symptoms (e.g., social and communication difficulties) and ADHD symptoms (e.g., disorganization, task avoidance, and hyperactivity). Conclusion ACEs were associated with adult ASD and ADHD traits and related symptom subdomains in adulthood.