Momentary Dynamics Implicate Emotional Features in the ADHD Phenotype.

Emotional dysregulation is increasingly recognized as important to the attention-deficit/hyperactivity disorder (ADHD) phenotype alongside inattention and hyperactivity-impulsivity. Studies of ADHD have relied primarily on trait-based conceptualizations that emphasize stability of symptoms across moderate developmental timescales (i.e., months to years). Trait-based conceptualizations provide a critical view but fail to account for short-term dynamic variations in the expression of ADHD symptoms and emotion. This leaves a gap in our understanding of the short-term variation in ADHD symptom expression and the dynamic relationships among ADHD symptoms and emotion. Here, we assessed caregiver report of ADHD symptoms and positive and negative emotion using ecological momentary approaches over 2 weeks in a sample of 36 children with and without ADHD between the ages of 7-12 years old. Between-person (RKF) and within-person (RC) reliability were estimated. Multilevel models tested specific covariation hypotheses between ADHD symptoms and emotion. Analyses confirmed that ADHD and emotion ratings were reliable as individual differences (i.e., between-person; RKF range 0.93-1.0) and moment-to-moment change (i.e., within-person; Rc range 0.66-0.88) measures. Multilevel models found little evidence for lagged effects between domains, but consistently identified concurrent expression of ADHD symptoms and emotions; inattention covaried most strongly with negative emotion and hyperactivity-impulsivity covaried most strongly with positive emotion. Results demonstrate the importance of complementing trait-level conceptualizations with assessment of momentary dynamics. Momentary assessment suggests important covariation of ADHD symptoms and emotion as part of the ADHD phenotype.

The Relationship Between Emotion Dysregulation and Error Monitoring in Adolescents with ADHD.

Attention-deficit/hyperactivity disorder (ADHD) is emblematic of the limitations of existing diagnostic categories. One potential solution, consistent with the Research Domain Criteria (RDoC) initiative, is to interrogate psychological mechanisms at the behavioral and physiological level together to try and identify meaningful subgroups within existing categories. Such approaches provide a way to revise diagnostic boundaries and clarify individual variation in mechanisms. Here, we illustrate this approach to help resolve heterogeneity in ADHD using a combination of behaviorally-rated temperament measures from the Early Adolescent Temperament Questionnaire; cognitive performance on three difference conditions of an emotional go/no-go task; and electroencephalogram (EEG)-measured variation in multiple stages of error processing, including the error-related negativity (ERN) and positivity (Pe). In a large (N = 342), well-characterized sample of adolescents with ADHD, latent profile analysis identified two ADHD temperament subgroups: 1) emotionally regulated and 2) emotionally dysregulated (with high negative affect). Cognitive and EEG assessment in a subset of 272 adolescents (nADHD = 151) found that the emotionally dysregulated group showed distinct patterns of change in early neural response to errors (ERN) across emotional task conditions as compared to emotionally-regulated ADHD adolescents and typically-developing controls. Both ADHD groups showed blunted later response to errors (Pe) that was stable across emotional task conditions. Overall, neural response patterns identified important differences in how trait and state emotion interact to affect cognitive processing. Results highlight important temperament variation within ADHD that helps clarify its relationship to the ERN, one of the most prominent putative neural biomarkers for psychopathology.

Electroencephalogram aperiodic power spectral slope can be reliably measured and predicts ADHD risk in early development.

The aperiodic exponent of the electroencephalogram (EEG) power spectrum has received growing attention as a physiological marker of neurodevelopmental psychopathology, including attention-deficit/hyperactivity disorder (ADHD). However, its use as a marker of ADHD risk across development, and particularly in very young children, is limited by unknown reliability, difficulty in aligning canonical band-based measures across development periods, and unclear effects of treatment in later development. Here, we investigate the internal consistency of the aperiodic EEG power spectrum slope and its association with ADHD risk in both infants (n = 69, 1-month-old) and adolescents (n = 262, ages 11-17 years). Results confirm good to excellent internal consistency in infancy and adolescence. In infancy, a larger aperiodic exponent was associated with greater family history of ADHD. In contrast, in adolescence, ADHD diagnosis was associated with a smaller aperiodic exponent, but only in children with ADHD who had not received stimulant medication treatment. Results suggest that disruptions in cortical development associated with ADHD risk may be detectable shortly after birth via this approach. Together, findings imply a dynamic developmental shift in which the developmentally normative flattening of the EEG power spectrum is exaggerated in ADHD, potentially reflecting imbalances in cortical excitation and inhibition that could contribute to long-lasting differences in brain connectivity.

The relationship between alpha asymmetry and ADHD depends on negative affect level and parenting practices.

Atypical frontal alpha asymmetry is associated with the approach/withdrawal and affective processes implicated in many psychiatric disorders. Rightward alpha asymmetry, associated with high approach, is a putative endophenotype for attention deficit/hyperactivity disorder (ADHD). However, findings are inconsistent, likely because of a failure to consider emotional heterogeneity within the ADHD population. In addition, how this putative risk marker interacts with environmental factors known to increase symptom severity, such as parenting practices, has not been examined. The current study examined patterns of alpha asymmetry in a large sample of adolescents with and without ADHD, including the moderating role of negative affect and inconsistent discipline. Resting-state EEG was recorded from 169 well-characterized adolescents (nADHD = 79). Semi-structured clinical interviews and well-validated rating scales were used to create composites for negative affect and inconsistent discipline. The relationship between alpha asymmetry and ADHD diagnosis was moderated by negative affect. Right asymmetry was present only for those with ADHD and low levels of negative affect. In addition, greater right alpha asymmetry predicted severity of ADHD symptoms for those with the disorder, but only in the context of inconsistent parenting practices. Results confirm right alpha asymmetry is a possible endophenotype in ADHD but highlight the need to consider emotional heterogeneity and how biological risk interacts with child environment in order to fully characterize its relationship to disorder liability and severity.