Etiological Networks of Attention-Deficit/Hyperactivity Disorder during Childhood and Adolescence

Abstract

Objective: The purpose of the current study was to use network analysis techniques to parse relations between attention-deficit/hyperactivity disorder (ADHD) symptom domains, domains of executive function, and temperament traits.

Methods: Participants were 420 children aged 6-17 years (55% boys). The majority of the participants were Caucasian (72.86%) and 50% of the sample met diagnostic criteria for ADHD. Both parents and teachers provided ratings of participants' ADHD symptom severity. Parents completed questionnaires pertaining to participants' temperament traits, and participants completed well-validated laboratory measures of executive function.

Results: Results suggested effortful control as demonstrating the strongest relations with ADHD, particularly the parent-reported inattentive symptom domain. Additionally, negative effects appeared to demonstrate weaker but still notable relations primarily with the parent-reported hyperactive/impulsive symptom domain. Measures of executive function did not appear to demonstrate relations with any measures of ADHD symptoms or temperament traits. The results were generally replicated in a distinct sample (n = 732, 7-13 years, 63% boys, 81% White), although differences emerged pertaining to the role of surgency (i.e., related to the hyperactive/impulsive symptom domain in the replication but not the primary sample).

Conclusions: Overall, findings provided support for the primary role of effortful control, as well as secondary roles for negative affect and surgency, as key risk markers for the characterization of ADHD. Additional exploration of the overlap between temperament and executive function, as pertaining to ADHD, may help clarify heterogeneity in phenotypes and suggest priorities for targeted interventions outside of traditional symptoms.

Figure 1

Primary Sample Networks Depicting Regularized Partial Correlations Among Parent-Reported ADHD Symptoms, Teacher-Reported ADHD Symptoms, Executive Function Domains, and Temperament Traits Note. Solid lines indicate positive correlations and broken lines indicate negative correlations. Line thickness indicates the strength of the relation. Listed edge weights correspond with regularized partial correlations.

Figure 2

Bridge Strength Values for Variables in (from left to right) Complete Networks, Networks Including Only Parent-Reported ADHD Symptoms, and Networks Only Including Teacher-Reported ADHD Symptoms in the Primary Sample Note. Nodes are listed on the y-axis, with bridge strength values listed on the x-axis. Values farther to the right indicate greater bridge centrality. IA = Inattentive Symptom Domain, HI = Hyperactive/Impulsive Symptom Domain, SSRT = stop signal reaction time, DS = digit span, TRAIL-A = trail making test condition A, TRAIL-B = trail making test condition B.