A critical appraisal of the role of neuropsychological deficits in preschool ADHD

The present study aimed at improving our understanding of the role of neuropsychological deficits in preschool Attention Deficit Hyperactivity Disorder (ADHD). The study included 52 children in the ADHD group and 72 controls (age 4–6 years). Both laboratory measures and teacher reports of executive deficits (i.e., working memory, inhibition, and shifting), delay-related behaviors (i.e., the preference for minimizing delay), and emotional functions (i.e., emotion recognition and regulation) were included. Variable-oriented analyses were complemented with person-oriented analyses (i.e., identifying the proportion of patients considered impaired). Results showed that the ADHD group differed from controls with regard to all measures of executive functioning and most measures of delay-related behaviors, but few differences were found for emotional functioning. A substantial subgroup (23%) of children with ADHD did not have a neuropsychological deficit in any domain. There were subgroups with executive or delay-related deficits only, but no pure emotional subgroup. The overlap between different neuropsychological deficits was much larger when teacher reports were used as opposed to laboratory measures. Regarding functional impairments, large mean differences were found between the ADHD group and controls. However, neuropsychological deficits were not able to explain individual variations in daily life functioning among children with ADHD. In conclusion, the present study identified some important methodological and theoretical issues regarding the role of neuropsychological functioning in preschool ADHD.     

Inhibition and working memory in young preschool children with symptoms of ADHD and/or oppositional-defiant disorder

Background: Early symptoms of attention deficit/hyperactivity disorder (ADHD) and oppositional-defiant disorder (ODD) are associated with deficits in cognitive self-regulatory processes or executive functions (EF)s. However, the hypothesis that neurocognitive deficits underlying the two disorders are already evident during early preschool years still has limited empirical support. The present study investigated associations between symptoms of ADHD and/or ODD and two core EFs, inhibition and working memory, in a large nonclinical sample of 3-year old children. Method: Participants were 1045 children (554 boys, age 37–47 months), recruited from the population based Norwegian Mother and Child Cohort Study (MoBa). Relations between behavioral symptoms and measures of inhibition and working memory were studied both categorically and dimensionally. Results: Children with co-occurring symptoms of ADHD and ODD performed at a significantly lower level than typically developing children in 4 out of 5 EF measures. Symptoms of ADHD, both alone and in combination with ODD, were associated with reduced performance on tests of inhibition in the group comparisons. Dimensional analyses showed that performance within both EF domains contributed to variance primarily in ADHD symptom load. The associations between test results and behavioral symptoms remained significant after gender and verbal skills had been controlled. Conclusion: Young preschoolers show the same pattern of relations between EF and behavioral symptoms of ADHD and/or ODD as previously described in older children diagnosed with ADHD and/or ODD. Effect sizes were generally small, indicating that measures of EF have limited clinical utility at this stage in development.     

Positive emotional attention bias in young children with symptoms of ADHD

Children with attention-deficit/hyperactivity disorder (ADHD) often experience emotional dysregulation. Dysregulation can arise from heightened attention to emotional stimuli. Emotional attention biases are associated with a number of adverse socioemotional outcomes including reward sensitivity and externalizing behaviors. As reward sensitivity and externalizing behaviors are common in children with ADHD, the aim of the current study was to determine whether emotional attention biases are evident in young children with clinically significant ADHD symptoms. To test this, children with (n = 18) and without (n = 15) symptoms of ADHD were tested on a Dot Probe task. Provided recent evidence that emotional attention biases are attenuated by sleep, the task was performed before and after overnight sleep. Children with ADHD symptoms displayed positive, but not negative, attention biases at both time points, whereas typically developing children did not preferentially attend toward or away from positive or negative stimuli. Sleep did not alter attention biases in either group. Collectively, these results indicate that children with ADHD symptoms have stable, positive attention biases.     

Equivalence of mother and father ratings of ADHD in children

Obtaining data from multiple informants provides a more comprehensive diagnostic picture in the assessment of attention deficit hyperactivity disorder (ADHD). Differences in symptom ratings have been observed between parent- and teacher-report scales, though less information is available regarding differences between mothers and fathers. To address this gap, this study examines the rater agreement between mothers and fathers on the Diagnostic and Statistical Manual of Mental Disorders – Fourth Edition (DSM-IV) ADHD Symptom Rating Scale (DSM-ADHD-SRS). The participants consisted of 337 children diagnosed with ADHD who underwent comprehensive neuropsychological assessment. Confirmatory factor analysis indicates that a three-factor model comprising inattention, hyperactivity, and impulsivity symptoms provides the best fit for both mothers’ and fathers’ ratings. Mothers provided higher mean ratings for the inattention scale. These results suggest that the factor structure for the DSM-ADHD-SRS is the same, regardless of parent gender. However, symptoms of inattention may vary depending upon which parent completes the ratings. This discrepancy could lead to differences in diagnostic impressions in clinical evaluations.     

A parent-report scale of behavioral inhibition: Validation and application to preschool-age children who do and do not stutter

PurposeThis two-part (i.e., Study 1, Study 2) study investigated behavioral inhibition (BI) in preschool-age children who do (CWS) and do not (CWNS) stutter. The purpose of Study 1 was to develop the Short Behavioral Inhibition Scale (SBIS), a parent-report scale of BI. The purpose of Study 2 was to determine, based on the SBIS, differences in BI between CWS and CWNS, and associations between BI and CWS’s stuttering frequency, stuttering severity, speech-associated attitudes, and stuttering-related consequences/reactions.MethodParticipants in Study 1 were 225 CWS and 243 CWNS with the majority of them being included in Study 2. In Study 2, a speech sample was obtained for the calculation of stuttering frequency and severity, and the parents of a subset of CWS completed the Communication Attitude Test for Preschool and Kindergarten Children Who Stutter (Vanryckeghem & Brutten, 2007), and the Test of Childhood Stuttering Disfluency-Related Consequences Rating Scale (Gillam, Logan, & Pearson, 2009).ResultsStudy 1 analyses indicated that SBIS is a valid and reliable tool whose items assess a single, relatively homogeneous construct. In Study 2, CWS exhibited greater mean and extreme BI tendencies than CWNS. Also CWS with higher, compared to CWS with lower, BI presented with greater stuttering frequency, more severe stuttering, greater stuttering-related consequences, and more negative communication attitudes (for CWS older than 4 years of age).ConclusionFindings were taken to suggest that BI is associated with early childhood stuttering and that the SBIS could be included as part of a comprehensive evaluation of stuttering.     

Anti-equality: Social comparison in young children

Young children dislike getting less than others, which might suggest a general preference for equal outcomes. However, young children are typically not averse to others receiving less than themselves. These results are consistent with two alternatives: young children might not have any preferences about others receiving less than themselves, or they might have preferences for others receiving less than themselves. We test these alternatives with 5- to 10-year-old children. We replicate previous findings that children will take a cost to avoid being at a relative disadvantage, but also find that 5- and 6-year-olds will spitefully take a cost to ensure that another’s welfare falls below their own. This result suggests that the development of fairness includes overcoming an initial social comparison preference for others to get less relative to oneself.     

Evaluating the endophenotype model of ADHD neuropsychological deficit: results for parents and siblings of children with ADHD combined and inattentive subtypes

Neurogenetic models predict neuropsychological weaknesses in the relatives of children with attention-deficit/ hyperactivity disorder (ADHD). The authors examined executive and regulatory measures in 386 relatives (307 parents, 79 siblings) of children with ADHD combined type, ADHD inattentive type, and controls. Predicted deficits were seen on trailmaking (relatives of ADHD combined type only), stop-signal reaction times (relatives of girls only), and response variability (mothers only) but not on naming or output speed. Effects generally held, even with relatives' ADHD status controlled. A neuropsychologically impaired subgroup of children with ADHD had relatives with clear neuropsychological weaknesses. The authors conclude that a neurogenetic model of ADHD etiology is supportable only for a subset of executive functions and that neuropsychological heterogeneity warrants more examination in ADHD.     

Relationship of temporal lobe volumes to neuropsychological test performance in healthy children

Ecological validity of neuropsychological assessment includes the ability of tests to predict real-world functioning and/or covary with brain structures. Studies have examined the relationship between adaptive skills and test performance, with less focus on the association between regional brain volumes and neurobehavioral function in healthy children. The present study examined the relationship between temporal lobe gray matter volumes and performance on two neuropsychological tests hypothesized to measure temporal lobe functioning (visual perception-VP; peabody picture vocabulary test, third edition-PPVT-III) in 48 healthy children ages 5-18 years. After controlling for age and gender, left and right temporal and left occipital volumes were significant predictors of VP. Left and right frontal and temporal volumes were significant predictors of PPVT-III. Temporal volume emerged as the strongest lobar correlate with both tests. These results provide convergent and discriminant validity supporting VP as a measure of the "what" system; but suggest the PPVT-III as a complex measure of receptive vocabulary, potentially involving executive function demands.     

Reversal learning in young children as a function of number of choice-alternatives

Discrimination learning and reversal problems were given to 128 children aged two and three years in which there were either two, three, six, or nine choice-alternatives per problem. The position of the correct object (either a toy car on the original problem and a ball on the reversal problem or vice versa) was varied randomly among all the possible positions, all other positions being occupied by duplicates of the incorrect object. It was found that two-choice reversal problems were much more difficult than all others. There was also a direct and monotonic relationship between ease of solution and number of choices present during reversal learning. Additional analysis inlicated that position response biases were probably responsible for this effect.     

Parent satisfaction with neuropsychological consultation after pediatric mild traumatic brain injury

Few studies have focused on consumer satisfaction following neuropsychological evaluation. We sought to examine parent satisfaction with neuropsychological consultation following a mild traumatic brain injury (TBI) in school-age children. We surveyed 71 parents of 8- to 17-year-olds participating in a prospective longitudinal study examining neuropsychological consultation as an intervention for persistent postconcussive symptoms. Children had sustained injuries between 2 and 12 months prior to enrollment. Neuropsychological consultation occurred on average 5 months post-injury. Parent satisfaction data were collected via telephone approximately 4 months after the neuropsychological consultation. The vast majority of parents were quite satisfied with the service (e.g., 94% overall satisfaction rate; 96% rated the service as good or excellent). Satisfaction rates were associated positively with time since injury and negatively with parental education. No other child, parent, or provider variable correlated with satisfaction. The results add to the relatively sparse literature on parent satisfaction with neuropsychological evaluation. A pressing future need in pediatric neuropsychology is to examine the satisfaction of other consumers of the service, including healthcare personnel, educators, and the child patients themselves.     

Sleep duration associates with moderate-to-vigorous intensity physical activity and body fat in 1- to 3-year-old children

Sleep during early childhood is important for many developmental outcomes and shows promise as an important correlate of both obesity risk and physical activity behaviors. This was a cross-sectional study concerning the relationships between sleep and moderate- to – vigorous intensity physical activity and body fat percentage in a sample of 1- to 3-year-old children (N = 50; ages 27.512 ± 10.363 months). Sleep was measured with a caregiver questionnaire. Sedentary time, light, moderate, vigorous, and moderate- to – vigorous intensity physical activity were measured with Actigraph wT3x-BT accelerometers. Body fat was measured using Air Displacement Plethysmography with the BodPod Pediatric Option. Moderate- to – vigorous intensity physical activity and body fat percentage both associated with sleep duration, controlling for age and accelerometer wear time. These factors combined explained 54.3 % of the variance in sleep duration present in the sample. These results suggest the presence of relationships between sleep and physical activity and body composition constructs in this sample. Sleep may be an important variable in efforts to both promote early childhood physical activity and healthy body composition.     

Postnatal exposure to methyl mercury and neuropsychological development in 7-year-old urban inner-city children exposed to lead in the United States

Background: The most common route for general population exposure to methyl mercury (MeHg) is fish consumption. Recommendations to pregnant women about consuming fish contaminated with MeHg are also applied to children, but there are few studies available about the effects of low-level postnatal MeHg exposure in them.

Objectives: To investigate the association between postnatal methyl mercury exposure and neuropsychological development in a study of children also exposed to lead, both measured at 7 years.

Methods: We measured MeHg concentrations in blood samples from the Treatment of Lead-Exposed Children (TLC) trial in which 780 children with elevated concentrations of lead in blood were followed with neuropsychological tests from ages 12–33 months through 7 years. Here we examine blood MeHg concentration and neuropsychological test scores, both measured at age 7 years. We used a maximum likelihood method to estimate geometric mean MeHg concentration and generalized linear regression models to analyze MeHg and neuropsychological test scores.

Results: Geometric mean MeHg concentration was 0.56 (95% confidence interval: 0.52, 0.59) μg/L. A 1 μg/L increase in MeHg was associated with a 2.1 (95% confidence interval: 0.4, 3.8) point increase in Full-Scale IQ and 0.2 (95% confidence interval: 0.02, 0.4) point increase in Learning Slopeindex T-score on a test of verbal memory.

Conclusions: Our results suggest that the relatively low MeHg exposure in US school-aged children from this population has no detectable adverse effect on neuropsychological development. The positive associations observed between MeHg and neurodevelopment may indirectly reflect consumption of beneficial polyunsaturated fatty acids from seafood.     

Effects of IQ on executive function measures in children with ADHD.

The present study compared children with Attention-Deficit Hyperactivity Disorder (ADHD) and controls on a selected set of clinical measures of executive function (EF). A total of 92 children (51 ADHD, 41 control), ages 6-16, completed measures chosen from a larger neuropsychological battery to illustrate diverse components of the EF construct (planning, inhibitory control, response preparation, memory search). The selected measures were moderately correlated with one another, and moderately correlated with IQ. After controlling for age, sex, presence of learning disability (LD), ADHD, and IQ test version, Full Scale IQ was significantly related to four of the five selected EF measures. A second analysis showed group differences on the EF measures at different IQ levels. After covarying for age, there was a significant multivariate effect for IQ level (average, high average, superior) and a significant multivariate interaction between group (ADHD vs. control) and IQ level. Three of the five selected EF measures showed significant univariate group effects (controls performing better than ADHD) at the average IQ level; however, there were no significant group differences between children with ADHD and controls at high average or superior IQ levels. These results suggest that clinical measures of EF may differ among children with ADHD and controls at average IQ levels, but there is poorer discriminatory power for these measures among children with above average IQ.     

Sleep in children enhances preferentially emotional declarative but not procedural memories

Although the consolidation of several memory systems is enhanced by sleep in adults, recent studies suggest that sleep supports declarative memory but not procedural memory in children. In the current study, the influence of sleep on emotional declarative memory (recognition task) and procedural memory (mirror tracing task) in 20 healthy children (10-13 years of age) was examined. After sleep, children showed an improvement in declarative memory. Separate analysis with respect to the emotional stimulus content revealed that sleep enhances the recognition of emotional stimuli (p > .001) rather than neutral stimuli (p = .084). In the procedural task, however, no sleep-enhanced memory improvement was observed. The results indicate that sleep in children, comparable to adults, enhances predominantly emotional declarative memory; however, in contrast to adults, it has no effect on the consolidation of procedural memory.     

Executive Functioning in Children and Adolescents with Major Depressive Disorder

The present investigation examined neurocognitive functioning, focusing on executive functioning (EF), in 39 children and adolescents with Major Depressive Disorder (MDD) and 24 healthy control subjects all ages 8 to 17 years. The Wechsler Intelligence Scale for Children-Third Edition along with several measures of executive functioning including the Wisconsin Card Sorting Task, Trail Making Test, Controlled Oral Word Association Test, and the Stroop Color Word Test were administered. The neurocognitive profiles for the group of depressed children and adolescents were grossly intact as most scores on intellectual and EF measures fell within the average range and did not differ from the comparison group. Mental processing speed was decreased in the MDD versus normal control group and 27% of the depressed group performed below average on the Trail Making Test. This investigation provided a good base from which to compare future literature on EF in outpatients with early-onset MDD.     

The Feasibility of Cognitive Screening of Patients with Ischaemic Stroke Using the Preliminary Neuropsychological Battery

In the present study, we assessed the reliability, validity and diagnostic accuracy of the non-verbal Preliminary Neuropsychological Battery (PNB) in a sample of stroke patients (n = 149) without significant aphasia and a sample of similarly aged healthy elderly controls (n = 122). The results indicate that as a brief bedside test of global cognitive function the PNB had satisfactory internal, external reliability and validity in this population and a cut-off point of ≤? 55 on the PNB had a sensitivity of 71% and specificity of 94% to detect significant cognitive impairments. Furthermore, better performance on the non-symbolic section of the PNB was associated improved with executive function. In common with other brief neuropsychological tests, the PNB was susceptible to ceiling, educational, functional capability and depression effects. The results here indicate that further research is needed to determine the utility of the PNB in a longitudinal cohort of aphasic and non-aphasic stroke survivors.