Peer-reviewed article

Longitudinal associations among autism and ADHD traits, social maladjustment, and mental health in school-aged children.

Eriko Hashimoto, Hiroyuki Ito, Megumi Hamada, Takahiro Nakajima, Nobuya Takayanagi et al. · 4 Aug 2026

Abstract

BACKGROUND: Neurodevelopmental disorder traits are associated with a range of psychosocial difficulties, yet the longitudinal processes linking these traits to mental health remain insufficiently explored. This study examined developmental associations among autism spectrum disorder (ASD) traits, attention-deficit/hyperactivity disorder (ADHD) traits, social maladjustment, and mental health from childhood through adolescence. METHODS: Longitudinal data were drawn from 9,619 students across 11 grade cohorts in mainstream classrooms. Cross-lagged structural equation modeling was used to estimate independent longitudinal associations among ASD traits, ADHD traits, social maladjustment, and mental health, while controlling for confounding factors. ASD and ADHD traits were modeled simultaneously to clarify their unique developmental patterns. RESULTS: ASD traits were consistently associated with later internalizing problems and peer difficulties. ADHD traits were associated with later internalizing and externalizing problems, as well as academic challenges and strained teacher-parent relationships. These associations differed by trait type, suggesting distinct developmental pathways. Several bidirectional associations also emerged: poorer mental health was associated with subsequent social maladjustment, which was subsequently linked to persistent developmental difficulties. CONCLUSIONS: The findings indicate that social maladjustment is involved in the longitudinal associations between developmental disorder traits and mental health and may shape developmental trajectories. These results highlight the need for comprehensive support approaches that consider peer relationships, learning environments, and family-school relationships.