Predicting ADHD Symptoms in Adolescents Using Error-Related Brain Potentials

Attention-Deficit Hyperactivity Disorder (ADHD) is a common childhood disorder, but its clinical course varies widely. It is unclear why some individuals experience a remission of their ADHD symptoms across development while others have symptoms persist into adulthood. Performance monitoring, which involves the ability to recognize errors and make behavioral adjustments, is one aspect of self-regulation that may contribute to symptom change. Both early (e.g,. error-related negativity, ERN) and later (e.g., error-related positivity, Pe) stages of performance monitoring can be quantified via event-related potentials, which reflect electrical brain activity in response to errors. Better performance monitoring, as indicated by larger amplitude brain responses to errors, is hypothesized to be associated with symptom improvement in ADHD. Method: As part of a larger longitudinal study, 75 participants (control= 35, ADHD= 40) completed behavioral ratings (parents and teachers) and semi-structured clinical interviews (parents) to assess ADHD symptoms. At annual follow-up visits 3-5 years later, ADHD assessment was repeated. Children also completed a computerized emotional go/no-go task while electroencephalogram was recorded. ERN and Pe were quantified on failed inhibitory trials during positive, negative, and neutral conditions. Results: ERN amplitudes did not differ between groups. During positive emotion conditions, controls had higher Pe amplitudes (M=9.34, SD=6.49) than ADHD participants (M=5.57, SD=5.62), F(1,71)= 5.64, p=.02. Among the ADHD group, higher Pe amplitude in positive emotion conditions predicted a greater decrease in ADHD symptoms after controlling for baseline symptom severity, b=-.40, p=.005. Conclusions: Performance monitoring may be one cognitive skill associated with remission of ADHD symptoms

Annual Research Review: Reaction time variability in ADHD and autism spectrum disorders: measurement and mechanisms of a proposed trans-diagnostic phenotype

BACKGROUND: Intraindividual variability in reaction time (RT) has received extensive discussion as an indicator of cognitive performance, a putative intermediate phenotype of many clinical disorders, and a possible trans-diagnostic phenotype that may elucidate shared risk factors for mechanisms of psychiatric illnesses. SCOPE AND METHODOLOGY: Using the examples of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD), we discuss RT variability. We first present a new meta-analysis of RT variability in ASD with and without comorbid ADHD. We then discuss potential mechanisms that may account for RT variability and statistical models that disentangle the cognitive processes affecting RTs. We then report a second meta-analysis comparing ADHD and non-ADHD children on diffusion model parameters. We consider how findings inform the search for neural correlates of RT variability. FINDINGS: Results suggest that RT variability is increased in ASD only when children with comorbid ADHD are included in the sample. Furthermore, RT variability in ADHD is explained by moderate to large increases (d = 0.63–0.99) in the ex-Gaussian parameter τ and the diffusion parameter drift rate, as well as by smaller differences (d = 0.32) in the diffusion parameter of nondecision time. The former may suggest problems in state regulation or arousal and difficulty detecting signal from noise, whereas the latter may reflect contributions from deficits in motor organization or output. The neuroimaging literature converges with this multicomponent interpretation and also highlights the role of top-down control circuits. CONCLUSION: We underscore the importance of considering the interactions between top-down control, state regulation (e.g. arousal), and motor preparation when interpreting RT variability and conclude that decomposition of the RT signal provides superior interpretive power and suggests mechanisms convergent with those implicated using other cognitive paradigms. We conclude with specific recommendations for the field for next steps in the study of RT variability in neurodevelopmental disorders

Working Memory Mediates Increased Negative Affect and Suicidal Ideation in Childhood Attention-Deficit/Hyperactivity Disorder

Children with attention-deficit/hyperactivity disorder (ADHD) are at greater risk for suicidal ideation and suicide attempts compared to those without ADHD. Increased risk is at least partially attributable to a subset of children with ADHD and comorbid depression or disruptive behavior disorders; however, the early predictors and mechanisms driving increased risk are not well understood. Here, we investigate the contributions of two candidate mechanisms for increased suicidal ideation in children with ADHD: executive function and negative affect. 623 clinically well-characterized, community-recruited children classified by research criteria as ADHD (n = 388) or typically-developing controls (n = 253) participated. Parent-report on the Temperament in Middle Childhood Questionnaire provided a measure of negative affectivity. Children completed laboratory tasks to measure response inhibition and working memory. Suicidal ideation was evaluated by parent report during a semi-structured interview and child responses on the Children’s Depression Inventory. Compared to typically developing controls, children with ADHD had higher rates of suicidal ideation, more negative affect, slower stop signal reaction times, and weaker working memory. Statistical path-model analyses confirmed the hypothesis that weaker working memory in ADHD statistically mediated increased negative affect. Weaker working memory also mediated and increased suicidal ideation in these cross sectional data. Findings were not attributable to comorbid disruptive behavioral disorders. Poor response inhibition did not reliably mediate negative affect or suicidal ideation. Impairment in working memory is an important early risk factor for suicidal ideation in children with ADHD, and may help in identifying children for prevention and early intervention efforts

Development of ADHD: salience of heterogeneity in child temperament and adolescent course

Attention-deficit/hyperactivity disorder (ADHD) represents a powerful entry point for developmental approaches to psychopathology due to its substantial role in early emergence of major life problems. One key issue concerns the role of early environmental risks in etiology and maintenance in the context of genetic liability. Here, psychosocial aspects of development need more attention. A second key issue is that phenotypic heterogeneity requires better resolution if actionable causal mechanisms are to be effectively identified. Here, the interplay of cognition and emotion in the context of a temperament lens is one helpful way forward. A third key issue is the poorly understood yet somewhat striking bifurcation of developmental course in adolescence, when a subgroup seems to have largely benign outcomes, while a larger group continues on a problematic path. A final integrative question concerns the most effective conceptualization of the disorder in relation to broader dysregulation. Key scientific priorities are noted

The relationship between early and late event-related potentials and temperament in adolescents with and without ADHD - Fig 2

<p>Illustration of the grand average ERP waveforms for the A) N170 at electrode site P7 and P8 collapsed, and B) P3b and LPP at electrode sites P3, P4, and Pz collapsed.</p

Depiction of an example experimental run.

<p>Depiction of an example experimental run.</p

Regression coefficients.

<p>Regression coefficients.</p