Neurocognitive and Symptom Trajectories of ADHD from Childhood to Early Adolescence

A longitudinal investigation of parental ratings and performance metrics for executive functioning and symptom severity in clinically referred youth with ADHD

There remains a knowledge gap concerning the persistence of attention deficit hyperactivity disorder (ADHD) over the longer term. The current study aimed to investigate the change in parent-rated, and performance-based metrics of executive functioning (EF) and the relationship between these EF metrics and ADHD symptoms in individuals with ADHD from childhood/adolescence to young adulthood. This was done by examining possible improvements in parent-rated EF and performance-based measures of inattention and inhibition over a three-year interval and their relationship to ADHD outcomes in 137 clinically referred youth with ADHD (mean age = 12.4 years, SD = 3.1). Participants' parents completed the Behavior Rating Inventory of Executive Function (BRIEF) and the Swanson-Nolan-Pelham Scale at baseline and follow-up. Participants completed the Conners' Continuous Performance Test, Version II (CPT II) at baseline and follow-up. Statistical analyses were performed with Linear Mixed Models. The sex- and age-standardized measures Commission and Hit reaction time (RT) subscales of the CPT II and parent-rated metacognitive, and behavior regulation composites of the BRIEF were largely stable between measuring points. CPT Omissions, Hit RT standard error (reaction time variability), and parent-rated ADHD symptom scores improved slightly. BRIEF composites and reaction time variability were related to ADHD symptoms using longitudinal data. Overall, behavioral aspects of EF, as observed by parents in the home context, appear to play a significant role in the trajectory of childhood ADHD.

The relationship between executive function, neurodevelopmental disorder traits, and academic achievement in university students

Difficulties with executive function have often been identified in individuals with various neurodevelopmental disorders such as Autism Spectrum Disorder (ASD), Attention-Deficit Hyperactivity Disorder (ADHD), and Developmental Co-ordination Disorder (DCD). Additionally, in childhood and adolescence, executive functioning is an important predictor of academic achievement. However, less research has explored these relationships in adult students, and those with a high level of neurodevelopmental disorder traits but no clinical diagnosis. Therefore, the current study aimed to assess whether ASD, ADHD, and DCD traits can predict academic achievement in university students, and whether traits of these neurodevelopmental conditions moderate the relationship between executive function and academic achievement. Both neurotypical students and those with a clinical diagnosis of a neurodevelopmental disorder were able to participate, with the majority being neurotypical. Participants completed four self-report questionnaires and provided a measure of academic achievement based on their university assignment results. Traits of ASD, ADHD, and DCD alone did not predict achievement, however, traits of ADHD and DCD significantly moderated the relationship between executive function and academic achievement. ASD traits did not significantly moderate this relationship. Implications and suggestions for future research are also discussed.

The three-year outcome of emotional symptoms in clinically referred youth with ADHD and their relationship to neuropsychological functions

Background

Further knowledge is needed regarding long-term outcome of emotional symptoms, and the interplay between these symptoms and neuropsychological functioning in youth with attention deficit hyperactivity disorder (ADHD).

Objective

We aimed to explore the effect of performance-based neurocognitive functions and parent-rated behavioral executive functioning (EF) on self-rated and parent-rated internalizing symptoms longitudinally in clinically referred youth with ADHD (n = 137; mean age = 12.4 years). We also aimed to examine the change in self-rated emotional symptoms in the ADHD group and a Control group (n = 59; mean age = 11.9 years).

Method

At baseline, and three years later, parents completed rating scales of their child’s ADHD symptoms (Swanson Nolan Pelham Scale, Version IV – SNAP-IV), emotional symptoms (Five To Fifteen Questionnaire, Strengths, and Difficulties Questionnaire), and EF (Behavior Rating Inventory of Executive Function). At the same time, the child completed self-report measures of Anxiety, Depression, and Anger Inventories (the Beck Youth Inventories) and neurocognitive measures (Conner’s Continuous Performance Test, Version II (CPT-II), Working Memory and Processing Speed composites (Wechsler Intelligence Scales). Statistical analyses were linear and logistic mixed models.

Results

Using longitudinal data, parent- and self-ratings of emotional symptoms were associated with parent-ratings of EF behavior in youth with ADHD. Plan/organizing deficits were associated with Anxiety and Anger over and above other metacognitive subscales, while Emotional Control was related to Anger over and above other behavior regulation subscales. In the ADHD group, Anger symptoms improved across measuring points. When controlling for age, Anxiety, and Depression symptoms were largely stable in both groups, however at higher levels in the ADHD group. The differences in anxiety and depression symptoms across groups decreased over time.

Conclusions

The current study emphasizes the importance of identification, monitoring, and treatment of emotional symptoms, and behavioral aspects of EF in youth with ADHD.

Shared Predictors of Academic Achievement in Children with ADHD: A Multi-Sample Study

OBJECTIVE

To identify common and shared predictors of academic achievement across samples of children with ADHD.

METHOD

Two clinically referred samples from New Zealand (1 n = 88, 82% boys; 2 n = 121, 79% boys) and two community samples from the United States (3 n = 111, 65% boys; 4 n = 114, 69% boys), completed similar diagnostic, cognitive and academic assessments. Hierarchical multiple regression analyses identified significant predictors of word reading, spelling, and math computation performance in each sample.

RESULTS

Entered after IQ, semantic language, age at testing, and verbal working memory emerged as consistent predictors of achievement across academic subjects and samples. Visual-spatial working memory contributed to variance in math performance only. Symptom severity explained limited variance.

CONCLUSIONS

We recommend evaluations of children with ADHD incorporate assessments of working memory and language skills. Classroom/academic interventions should accommodate reduced working memory and address any identified language weaknesses.

Atypical Developmental Trajectories of Early Perception Among School-Age Children With Attention Deficit Hyperactivity Disorder During a Visual Search Task

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by cognitive deficits associated with attention. Prior studies have revealed the potential impact of ADHD on basic perception and cognitive ability in patients with ADHD. In this study, bilateral posterior P1 and N1 were measured in 122 Chinese children aged 7-12 years (64 with ADHD) to investigate the developmental characteristics of early perception during visual processing in school-age children with ADHD. For children with ADHD, a larger P1 activity with an atypical developmental pattern was evoked and observed for the visual search performance. These findings offer new insights into the mechanisms of cognitive developmental deficits and intervention techniques in children with ADHD.

Pre-attention and Working Memory in ADHD: A 25-Year Follow-Up Study

Objective: The aim of the study was to compare the development of working memory and preliminary stages of attentional processing in individuals with ADHD over a 23- to 25-year period. Method: Individuals with ADHD (n = 19) and healthy controls (n = 26) were followed up after 13 years (T2) and 23 to 25 years (T3) after initial assessment (T1). They were reassessed with diagnostic measures and the Backward masking task (pre-attention) and the Digit span distractibility test with and without distraction conditions (working memory). Results: The ADHD group performed below the healthy controls on all time points on the Digit span distractibility test. On the distractibility condition, we found a selective decline in performance from T2 to T3 for the ADHD group. Conclusion: The results highlight that ADHD individuals continue to display working memory deficits, also in adulthood, thus creating an imperative for cognitive rehabilitation techniques to help address attention difficulties.

A longitudinal investigation of cognitive functioning and its relationship to symptom severity and academic functioning in treatment seeking youth with AHDH

Background:

Children with ADHD tend to present with poorer cognitive functioning leaving them more vulnerable to a range of negative outcomes. To date, only a handful of longitudinal studies have examined the stability of Wechsler composite scores in children and adolescents with ADHD, and none of them used a more recent version of the Wechsler Intelligence Scales for Children (WISC), than the WISC-III.

Objective:

The present study investigates the cognitive stability and its longitudinal relationship with the severity of the child’s ADHD symptoms and school grades.

Method:

Cognitive functioning was measured with the fourth editions of the WISC-IV or the Wechsler Adult Intelligence Scales (WAIS-IV) at baseline and at a 3-4-year follow-up in children with ADHD (n = 125, mean age = 11.40 years, SD = 3.27) and a Control group of schoolchildren (n = 59, mean age = 11.97 years, SD = 2.15). The stability of cognitive functioning and the relationship between cognitive functioning, ADHD and grades were evaluated using linear mixed models and logistic regression.

Results:

Standardized composite scores of Full scale IQ, Verbal Comprehension, and Processing Speed declined between baseline and follow-up in the ADHD group. ADHD symptom scores were associated with Working Memory scores. Together, the severity of concurrent ADHD symptoms and lower scores for verbal comprehension at baseline and follow-up were associated with an increased risk of not achieving grades at follow-up in youth with ADHD.

Conclusions:

Youth with ADHD often present with cognitive impairments, not improved over time. Together these increase the risk of poorer academic outcomes. Concurrent evaluation of symptom severity and cognitive functions can add potentially useful information in terms of treatment planning, and school supports to prevent school failure.

Development of ADHD: Etiology, Heterogeneity, and Early Life Course

ADHD represents a powerful entry point for developmental approaches to psychopathology due to its major 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 seem to have largely benign outcomes, while a larger group continue 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.

Executive and non-executive functions in low birthweight/preterm adolescents with differing temporal patterns of inattention

Objective

This study assesses whether low birthweight/preterm (LBW/PT) adolescents with persistent inattention (PIA) have neuropsychological deficits that distinguish them from adolescents with school age limited inattention (SAL) and those largely unaffected (UA).

Method

Three latent classes (PIA, SAL, UA), derived from an earlier analysis of a LBW/PT birth cohort were compared on non-executive and executive functioning measures assessed at age 16.

Results

The PIA class displayed the poorest performance on executive functioning, which was exaggerated in the context of lower IQ. The PIA and the SAL classes had poorer performance on non-executive functioning relative to the UA class. Both types of functioning mediated the relationship of class to school service use and grade retention.

Conclusion

Neuropsychological impairment characterizes children and adolescents with inattention problems. Problems in executive functioning characterize the subset whose inattention persists through adolescence. Subsequent research can examine the potential for remediating these deficits to address academic and social problems.