Emotion regulation as a transdiagnostic link between ADHD and depression symptoms: evidence from a network analysis of youth in the ABCD study.

Background: Childhood ADHD is associated with greater risk of depression in adolescence and adulthood, with emotion regulation (ER) identified as a potential mediator. However, it remains unclear how distinct domains of ER differentially relate to ADHD and depression symptoms in early adolescence.

Methods: The current analysis estimated a network model using longitudinal, parent-reported data from the Adolescent Brain and Cognitive Development (ABCD) Study 5.1 Data Release in 2023 (n = 4,460 complete cases). Nodes were item-level ADHD symptoms averaged across ages 9-12, ER domains (Catastrophize, Distracted, Attuned, and Negative Secondary Emotions) at ages 12-13, and item-level depression symptoms at ages 13-14. In exploratory analyses, we also examined potential differences in network structure and connectivity by sex, history of ADHD diagnosis at ages 9-12, and ADHD polygenic score (PGS).

Results: Catastrophize and Distracted were the most important ER bridges between earlier ADHD and later depression symptoms in the network. Two distinct pathways emerged: inattentive ADHD symptoms were linked to depression symptoms (poor eating, feeling worthless) via the Distracted ER dimension, while hyperactive-impulsive ADHD symptoms were linked to depressed mood and anhedonia via the Catastrophize ER dimension. Exploratory network comparisons found similar networks by sex, structural differences by history of ADHD diagnosis, and differences in structure and connectivity by ADHD PGS.

Conclusions: Multiple pathways from ADHD in childhood to depression in early adolescence may include ER difficulties through catastrophizing and distraction when upset. A denser, more interconnected network of symptoms was found among youth with higher genetic liability to ADHD.