Does emotion dysregulation mediate the association between ADHD symptoms and internalizing problems? A longitudinal within‐person analysis in a large population‐representative study

BACKGROUND: Previous research has suggested that children with attention‐deficit/hyperactivity disorder (ADHD) symptoms commonly show emotion dysregulation difficulties. These difficulties may partly explain the strong tendency for internalizing problems such as anxiety and depression to co‐occur with ADHD symptoms. However, no study has yet provided a longitudinal analysis of the within‐person links between ADHD symptoms, emotion dysregulation, and internalizing problems necessary to examine this hypothesis from a developmental perspective. METHODS: We used data from the age 3, 5, and 7 waves of the large UK population‐representative Millennium Cohort Study (n = 9,619, 4,885 males) and fit gender‐stratified autoregressive latent trajectory models with structured residuals (ALT‐SR) to disaggregate within‐ and between‐person relations between ADHD symptom, emotion dysregulation, and internalizing problem symptoms. RESULTS: We found that emotion dysregulation significantly mediated the longitudinal within‐person association between ADHD symptoms and internalizing problems. CONCLUSIONS: Results underline the promise of targeting emotion dysregulation as a means of preventing internalizing problems co‐occurring with ADHD symptoms.