Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation


Arts and Sciences



First Advisor

Dr. Michelle M. Martel


Co-occurrence of attention-deficit/hyperactivity disorder (ADHD) with depression or anxiety (i.e., internalizing disorders) is a major route to poor outcomes, with temperament traits presenting as potential shared risk markers that underlie these disorders’ development and characterization. Prior work investigating the nature of ADHD-internalizing disorder co-occurrence using structural equation modeling has provided support for both temperament-based common cause (i.e., effortful control and negative affect as liabilities for multiple disorders) and direct causation (i.e., ADHD directly contributing to risk for internalizing disorders) effects separately. Using a network approach, the current study represented the first attempt to integrate these effects into one model while parsing heterogeneity in the trait-symptom and symptom-symptom relations within them. Participants were 799 children and adolescents aged 7-13 years at baseline (61.20% boys, 85.11% White; 59.57% diagnosed with ADHD). Across two measurement points approximately five years apart (i.e., Year 1, Year 6), parents/caregivers provided ratings of participants’ ADHD symptoms and temperament traits and participants provided ratings of depressive and anxiety symptoms. Pertaining to ADHD-depression networks, results suggested effortful control and, particularly, negative affect as transdiagnostic risk markers via relations with symptoms of both disorders. Simultaneously, depressive symptoms associated with reductions in perceived self-competence and difficulty making friends were uniquely related to several ADHD symptoms in Year 1, and ADHD inattentive symptoms (i.e., loses things; does not follow through; has difficulty sustaining attention) were uniquely related to depressive symptoms associated with reductions in perceived self-competence, distress/hopelessness, low self-worth, and difficulty making friends in Year 6. Examination of ADHD-anxiety networks suggested limited heterogeneity in symptom-symptom relations, although negative affect emerged as a core transdiagnostic risk marker via relations with inattentive and hyperactive/impulsive ADHD symptoms and anxiety symptoms associated with somatic problems and peer-related fears. Comparison of network findings with those of structural equation modeling approaches to conceptualizing common cause and direct causation effects suggested consistent and complementary results. No differences were identified in the structure of networks across Years 1 and 6, as well as gender. Continued clarification of specific and unique common cause and direct causation effects in the context of one another may help identify those most influential to the development and characterization of ADHD-internalizing disorder co-occurrence, with a focus on such effects potentially highlighting targets for screening tools and interventions that address and account for symptoms of multiple disorders.

Digital Object Identifier (DOI)

Funding Information

This study was supported by the National Institutes of Health under grant numbers R01MH119119-01A1 (PI: Michelle Martel) in 2019 and R37-MH-59105 (PI: Joel Nigg) in 2014.