Cognitive functioning and family risk factors in relation to symptom behaviors of ADHD and ODD in adolescents.

OBJECTIVE: In this study, the authors investigated whether ADHD and oppositional defiant disorder (ODD) behaviors share associations with problems in cognitive functioning and/or family risk factors in adolescence. This was done by examining independent as well as specific associations of cognitive functioning and family risk factors with ADHD and ODD behaviors. METHOD: A sample of 120 adolescents from the general population was assessed on various cognitive tasks. ADHD and ODD behaviors were measured through parental and teacher ratings based on Diagnostic and Statistical Manual of Mental Disorders (4th edition) criteria. Parents and adolescents provided information regarding measures of family risk factors. RESULTS: The results show that only cognitive functioning was associated with ADHD behaviors, and family risk factors were, independent of cognitive functioning, associated with ODD behaviors. CONCLUSION: These results suggest that cognitive performance bears a specific significance for ADHD behaviors, whereas family risk factors have specific importance for ODD behaviors.

Effects of symptoms of ADHD, ODD, and cognitive functioning on social acceptance and the positive illusory bias in children.

OBJECTIVE: To examine the effects of symptoms of ADHD and ODD and cognitive functioning on social acceptance and positive bias in children. METHOD: The sample consisted of 86 children (49 girls) between 7 and 13 years old, recruited to reflect a wide range of ADHD symptoms. Parents and teachers reported on ADHD and ODD symptoms and social acceptance. Children reported on social acceptance and were given tasks measuring working memory, inhibition and reaction-time variability. A discrepancy score between child and adult reports of social acceptance was used as a measure of positive bias. RESULTS: Inattention independently explained variance in social acceptance. The cognitive factors were related to social acceptance and the positive bias, but not beyond the ADHD and ODD symptoms. CONCLUSION: It is primarily disruptive behavior that contributes to external reports of children's social acceptance.

Behavioral and ERP indices of response conflict in Stroop and flanker tasks.

We investigated effects of different proportions of incongruent trials on behavioral and event-related potential (ERP) interference measures associated with response conflict in the Stroop and flanker task. From the literature, we hypothesized that response conflict is greater when incongruent trials are rare compared to when incongruent trials are frequent. In support, the behavioral results on both tasks and the ERP results on the Stroop task (N450) showed that interference effects were significantly larger when incongruent trials were rare than frequent. In contrast, the ERP results on the flanker task N200 showed a larger interference effect when incongruent trials were frequent than rare. Because results for the flanker N200 were opposite to behavioral effects and theoretical predictions, our findings challenge the notion of the flanker N200 as a valid index of response conflict.

Developmental change in the relation between simple and complex spans: a meta-analysis.

In the present meta-analysis the effects of developmental level on the correlation between simple and complex span tasks were investigated. Simple span-complex span correlation coefficients presented in 52 independent samples (7,060 participants) were regressed on a variable representing mean age of sample (range: 4.96-22.80 years), using analyses adapted for meta-analytic purposes. The results showed strong positive relations between mean age of sample and simple span-complex span correlation coefficients, suggesting that the relation between simple and complex span tasks became stronger with increasing age. These results could not be accounted for by study-related differences in measurement reliability, restricted range, or sample size. A new theoretical account explaining these findings is outlined.

Intellectual deficits in children with ADHD beyond central executive and non-executive functions.

This study aimed to specify the deficit in intellectual ability in children with attention deficit hyperactivity disorder (ADHD), by studying the mediating role of impairments in central executive function (EF)-related components (working memory, inhibition, sustained attention) and non-EFs (short-term memory and processing speed). Two hundred and thirty children aged 8-11 years from a population-based sample were assigned to either the ADHD group, the clinical comparison group, or the normal comparison group. The results showed that children with ADHD had poorer fluid and crystallized intelligence, relative to both comparison groups. Further, regarding fluid intelligence, these deficits were not fully mediated by, but rather went beyond, poorer functioning on the studied EF-related components and non-EFs. We tentatively interpret these fluid deficits in children with ADHD as representing deficiencies in a general intellectual resource reflecting executive attentional processes. Concerning crystallized ability, in contrast, the deficit signified impairment in the studied cognitive functions, as indicated by the significant full mediation effect.

Motor response inhibition and execution in the stop-signal task: development and relation to ADHD behaviors.

The main aim of this study was to investigate the developmental course of motor response inhibition and execution as measured by the stop-signal task in a population-based sample of 525 4- to 12-year-olds. A further aspiration of the study was to enhance the limited knowledge on how the various stop-signal measures relate to ADHD behaviors in a normal sample. We also wanted to contribute to the theoretical understanding of the various stop-signal measures by examining the relations between the stop-signal measures and performance on tasks reflecting other aspects of response inhibition and execution. Our results showed that the ability to inhibit as well as to execute a motor response as measured by the stop-signal task improved with age during childhood. Of specific interest are the findings suggesting that this task captures the development of motor response inhibition in the late preschool years (age 5 years). Both of the inhibition measures derived from the stop-signal task (i.e., SSRT and probability of inhibition) related significantly to teacher ratings of inattention as well as to performance on tasks tapping other aspects of inhibition. The data provided by this study have thus contributed to the scarce knowledge on early development of motor response inhibition, as well as suggested that the stop-signal task may be a valuable tool for capturing deficient motor response inhibition in ADHD behaviors in normal samples.