Working memory and inhibitory control deficits in children with ADHD: an experimental evaluation of competing model predictions.

Introduction: Children with ADHD demonstrate difficulties on many different neuropsychological tests. However, it remains unclear whether this pattern reflects a large number of distinct deficits or a small number of deficit(s) that broadly impact test performance. The current study is among the first experiments to systematically manipulate demands on both working memory and inhibition, with implications for competing conceptual models of ADHD pathogenesis. Method: A clinically evaluated, carefully phenotyped sample of 110 children with ADHD, anxiety disorders, or co-occurring ADHD+anxiety (Mage=10.35, 44 girls; 69% White Not Hispanic/Latino) completed a counterbalanced, double dissociation experiment, with two tasks each per inhibition (low vs. high) x working memory (low vs. high) condition. Results: Bayesian and frequentist models converged in indicating that both manipulations successfully increased demands on their target executive function (BF10>5.33x108, p<.001). Importantly, occupying children's limited capacity working memory system produced slower response times and reduced accuracy on inhibition tasks (BF10>317.42, p<.001, d=0.67-1.53). It also appeared to differentially reduce inhibition (and non-inhibition) accuracy for children with ADHD relative to children with anxiety (BF10=2.03, p=.02, d=0.50). In contrast, there was strong evidence against models that view working memory deficits as secondary outcomes of underlying inhibition deficits in ADHD (BF01=18.52, p=.85). Discussion: This pattern indicates that working memory broadly affects children's ability to inhibit prepotent tendencies and maintain fast/accurate performance, and may explain the errors that children with ADHD make on inhibition tests. These findings are broadly consistent with models describing working memory as a causal mechanism that gives rise to secondary impairments. In contrast, these findings provide evidence against models that view disinhibition as a cause of working memory difficulties or view working memory as a non-causal correlate or epiphenomenon in ADHD.

Relational victimization prospectively predicts increases in error-related brain activity and social anxiety in children and adolescents across two years.

Recent research has focused on identifying neural markers associated with risk for anxiety, including the error-related negativity (ERN). An elevated ERN amplitude has been observed in anxious individuals from middle childhood onward and has been shown to predict risk for future increases in anxiety development. The ERN is sensitive to environmental influences during development, including interpersonal stressors. Of note, one particular type of interpersonal stressor, relational victimization, has been related to increases in anxiety in adolescents. We tested whether relational victimization predicts increases in the ERN and social anxiety symptoms across two years in a sample of 152 child and adolescent females (ages 8 - 15). Results indicated that children and adolescents' baseline ERN was positively related to the ERN two years later. Furthermore, greater relational victimization at baseline predicted greater increases in the ERN two years later, controlling for baseline ERN. Moreover, relational victimization at baseline predicted increases in social anxiety, and this relationship was mediated by increases in the ERN. These results suggest that relational victimization impacts the developmental trajectory of the neural response to errors and thereby impacts increases in social anxiety among children and adolescents.

The impact of punishment on error-related brain activity in children.

The error-related negativity (ERN) is sensitive to individual differences relating to anxiety and is modulated by manipulations that increase the threat-value of committing errors. In adults, the ERN magnitude is enhanced when errors are followed by punishment, especially among anxious individuals. Punitive parenting is related to an elevated ERN in children; however, the effects of task-based punishment on the ERN in children have yet to be understood. Furthermore, there is a need to assess developmental periods wherein the ERN might be especially prone to modulation by punishment. We examined the impact of punishment on the ERN in a sample of children and assessed whether the impact of punishment on the ERN was moderated by age and anxiety. Punishment potentiated the ERN in children, especially among higher trait-anxious individuals; the punishment potentiation of the ERN was also associated with older age. The interaction between child age and anxiety symptoms did not significantly predict the punishment potentiation of the ERN; however, both child age and anxiety symptoms uniquely predicted the punishment potentiation of the ∆ERN. Anxious children may be especially prone to punishment-related alterations in error monitoring, and the impact of punishment on the ERN may become more pronounced as children age.

Development of the MIND: a Screening Measure Assessing Mental Health Treatment Needs.

Early identification and treatment of mental illness symptoms results in better outcomes, yet few screeners are available that can be efficiently used in community settings. The Mental Illness Needs Detection (MIND) Screener was developed to identify the need for mental health treatment and administered to 820 adults across the USA. Confirmatory factor analysis supported the internal consistency of the MIND. The MIND significantly correlated with the Kessler-10 (K10; a well-validated screener), reported mental illness, mental health treatment, and the need for treatment. The MIND's ability to accurately assess treatment needs was further demonstrated through high sensitivity (84%; 83%), specificity (71%; 62%), and AUC values (0.77; 0.73) when compared to both the K10 and reported need for treatment, respectively. These findings support the validity and reliability of the MIND and indicate its promise as a means of detecting a wide range of mental health needs across a variety of settings.

Rumination and the mood-as-input hypothesis: Does congruence matter?

BACKGROUND AND OBJECTIVES: The mood-as-input hypothesis (MAIH), which emphasizes the role of mood and stop rules on perseverative thinking, has been extensively studied in relation to worry (Meeten & Davey, 2011). However, relatively few studies have focused on the applicability of the MAIH to depressive rumination. Consequently, two studies were conducted to further examine the potential relevance of the MAIH to depressive rumination. METHODS: In the first study, a sample of undergraduate students completed a rumination interview under one of four conditions, including mood (positive vs. negative) and stop rule (as-many-as can (AMA) and feel like stopping (FL)). It was anticipated that participants in the negative mood/AMA and the positive mood/FL conditions would exhibit the most persistence in the rumination interview. A second, follow-up study was conducted in which a positive rumination condition was added to examine the role of congruence between mood induction and task valence on interview performance. RESULTS: In the first study, support for predictions of the MAIH was found in the negative mood conditions but not the positive mood conditions. In the second study, as predicted, under conditions of mood congruence, the original predictions of the MAIH were supported. However, under conditions of mood incongruence, participants appeared to default to the assigned stop rule. LIMITATIONS: Although the findings are promising, it is noteworthy that the sample was non-clinical. Further, this approach to studying depressive rumination may have somewhat limited ecological validity, as the research was conducted in a controlled laboratory setting. CONCLUSIONS: Overall, the current findings provide insight into the conditions under which depressive rumination is most likely to occur.