Heritability and Clinical Characteristics of Neuropsychological Profiles in Youth With and Without Elevated ADHD Symptoms

Effortful Control Protects Against Familial Liability for ADHD: Longitudinal Results from the ABCD Study in the United States

Effortful control, the ability to regulate complex and goal-directed behavior, may protect individuals from developing mental health symptoms. This study tested the potential for child effortful control and executive functioning to buffer the effects of familial liability for attention deficit hyperactivity disorder (ADHD) problems across a one-year timeframe. Data from the prospectively-collected Adolescent Brain Cognitive Development (ABCD)® study were used to examine whether caregiver-rated child effortful control and executive functioning moderated the association between familial ADHD risk and later ADHD symptoms in a sample of children (N = 6,133; ages 9-10 years at baseline). Two independent variables were considered to compare the predictive powers of specific (family ADHD) and broad (family psychopathology) risk factors. Two additional moderating variables (surgency, negative affect) were tested to examine specificity of effortful control and executive functioning as moderators. All variables of interest were measured on a continuum and via caregiver report. At high levels of effortful control and executive functioning, there was no association between familial liability for ADHD or broad psychopathology and later child ADHD problems. The moderator effects were specific to effortful control and executive functioning domains. Etiological models of heritable psychiatric disorders, such as ADHD, should consider the risk and protective contributions of individual traits, such as effortful control and executive functioning. Clinical prevention and intervention efforts may target self-regulation skills in children to buffer against familial liability for ADHD problems.

The Impact of Sex on Cognitive Control in ADHD: Girls Slow to Inhibit, Boys Inhibit Less, and Both Show Higher Response Variability

OBJECTIVE

To determine whether girls and boys with ADHD show distinct impairments in components of cognitive control across multiple tasks (go/no-go, stop signal, and flanker) and performance metrics (response speed, variability, and errors).

METHOD

A total of 300 children, ages 8 to 12 years with ADHD (n = 210, 58 girls) or typically developing (TD; n = 99, 37 girls), completed all tasks. Traditional response measures (e.g., mean and standard deviation of reaction time, inhibition errors, and stop signal reaction time) and ex-Gaussian modeling of reaction times (mu, sigma, and tau) were analyzed.

RESULTS

Girls showed intact response inhibition in the context of slower response speed, while boys made more inhibition errors and did not slow their response speed. Both girls and boys with ADHD showed higher response variability and poorer interference control than TD children.

CONCLUSION

Girls and boys with ADHD show distinct impairments in cognitive control that may be important for understanding the pathophysiology of ADHD.

Longitudinal Stability of Neural Correlates of Pediatric Attention Deficit Hyperactivity Disorder: A Pilot Study of Event Related Potentials and Electroencephalography

OBJECTIVE

Stability and developmental effects of electroencephalography (EEG) and event related potential (ERP) correlates of ADHD are understudied. This pilot study examined stability and developmental changes in ERP and EEG metrics of interest.

METHODS

Thirty-seven 7 to 11-year-old children with ADHD and 15 typically developing (TD) children completed EEG twice, 11 to 36 months apart. A series of mixed effects linear models were run to examine stability and developmental effects of EEG and ERP metrics.

RESULTS

Stability and developmental effects of EEG and ERP correlates of ADHD varied considerably across metrics. P3 amplitude was stable over time and showed diverging developmental trajectories across groups. Developmental differences were apparent in error related ERPs and resting aperiodic exponent. Theta-beta ratio was stable over time among all children.

CONCLUSIONS

Developmental trajectories of EEG and ERP correlates of ADHD are candidate diagnostic markers. Replication with larger samples is needed.

Neural activation, cognitive control, and attention deficit hyperactivity disorder: Evaluating three competing etiological models

BACKGROUND

Cognitive control impairments are observed across several psychiatric conditions, highlighting their role as a transdiagnostic marker. Individuals with attention deficit hyperactivity disorder (ADHD) have difficulties with inhibition, working memory, processing speed, and attention regulation. These cognitive control impairments may either mediate or moderate the association between neurobiological vulnerabilities and phenotypic presentation in neurodevelopmental disorders. Alternately, neurocognitive vulnerabilities in ADHD may be additive, akin to a multiple deficit model. We tested the mediation, moderation, and additive models using neurocognitive data in youth with ADHD.

METHODS

7-11 year-old children diagnosed with ADHD (n = 75) and control children (n = 29) completed EEG recordings and neuropsychological testing (full scale IQ; cognitive control). Caregivers provided ADHD symptom ratings. Correlations and linear regression analyses were completed to examine the associations among cortical functioning (aperiodic slope), cognitive control, and ADHD symptoms.

RESULTS

We found support for an additive model wherein vulnerabilities in aperiodic slope, event-related potentials, and cognitive control each explained unique variance in ADHD symptoms. There was some evidence that cognitive control moderates the effect of atypical cortical development on ADHD symptoms. There was no support for the mediation model.

CONCLUSIONS

The etiology of ADHD symptoms is multifaceted and involves multiple "hits" across neurological and cognitive-behavioral factors.

The Structure and Diagnostic Accuracy of the QbTest in Pediatric ADHD: A Retrospective Clinical Study

OBJECTIVE

The QbTest that combines a continuous performance task (CPT) with a motion-tracking system may help identify attention deficit hyperactivity disorder (ADHD). This study examined the structure and diagnostic ability of the QbTest in children and adolescents.

METHOD

Retrospective data from 1,274 children and adolescents were analyzed. The study assessed data on a principal component analysis (PCA), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

The QbActivity component included the variables micro-events, distance, area, and time active; the QbImpulsivity included normalized commissions and commissions (anticipatory errors were added in a version for 6-12-year-olds only); and the QbInattention included omissions, reaction time, and reaction time variation. Sensitivity ranged between 22% and 50%, specificity 79% and 96%, PPVs 40% and 95%, and NPVs 24% and 66%.

CONCLUSION

The structure of the QbTest with three cardinal parameters and nine/ten CPT and motion analysis variables was supported. The diagnostic accuracy was found to be poor to moderate. Given that this is a retrospective study, the interpretation of diagnostic accuracy should be considered within this context.

The role of single trial variability in event related potentials in children with attention deficit hyperactivity disorder

OBJECTIVE

Children with attention deficit hyperactivity disorder (ADHD) show attenuated mean P3 component amplitudes compared to typically developing (TD) children. This finding may be the result of individual differences in P3 amplitudes, P3 latencies, and/or greater single trial variability (STV) in amplitude or latency, suggesting neural "noise."

METHODS

Event related potentials (ERPs) from 75 children with ADHD and 29 TD children were recorded with electroencephalography (EEG). Caregivers provided ratings on child ADHD symptoms. Single-trial ERP amplitudes and latencies were extracted from the P3 component time window during a visual oddball task. Additionally, we computed individual-centered and trial-centered P3 amplitudes to account for inter-individual and inter-trial variability in the timing of the P3 peak.

RESULTS

In line with prior research, greater ADHD symptom severity was associated with reduced mean P3 amplitude. This correlation was no longer significant after correcting for inter-trial differences in P3 latency. In contrast, greater ADHD symptom severity was associated with reduced STV in P3 amplitude.

CONCLUSIONS

Our results suggest that attenuated average P3 amplitude in ADHD samples is due to a consistent reduction in strength of the neurophysiological signal at the single trial level, as well as increased inter-trial variability in the timing of P3 peak amplitudes. The traditional method of extracting P3 amplitudes based on a single time window for all trials may not adequately capture variability in P3 latencies associated with ADHD.

SIGNIFICANCE

Inter- and intra-individual differences in brain signatures should be considered in models of neurobiological differences in neurodevelopmental samples.