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.     

Do Childhood Emotional Lability and ADHD Symptoms Have Shared Neuropsychological Roots?

Emotional Lability (EL) is a source of impairment in multiple mental disorders of children, including attention-deficit/hyperactivity disorder (ADHD). It has been proposed that the overlap between EL and ADHD symptoms is the result of common neuropsychological deficits. The aim of the present study was to test this hypothesis by using a multi-method approach. In a mixed sample of 61 children (49 community sample and 12 children with an ADHD diagnosis) aged between 8 and 12 years, we examined the relationship between parental reports of ADHD and EL, real-time children’s emotional expressions in an experimental context, children’s performance on neuropsychological tasks and parental ratings of neuropsychological functioning. Parental EL ratings were significantly predicted by task-based reaction time variability and by questionnaire measures of Self-Direction & Organization and Arousal Regulation. Parental EL ratings were also significantly related to both ADHD symptom dimensions. After controlling for shared neuropsychological factors, ADHD symptoms no longer predicted parental EL ratings. Neuropsychological task performance was not significantly related to real time emotional expressions. However, positive emotional expressions were significantly predicted by higher parental ratings of Cognition and negative emotional expressions by parental ratings of low Effort engagement – accounting for some of the correlation with ADHD symptoms. The current results highlight the plausible role of cognitive energetic processes in explaining the EL and ADHD symptom association.

     

The Association between Self-Regulation and Symptoms of Autism Spectrum Disorder in Preschoolers with Externalizing Behavior Problems

The purpose of the current study was to examine the role of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) symptoms in predicting deficits in self-regulation across the domains of executive functioning and emotion regulation. Parents of 40 preschoolers with externalizing behavior problems reported on children’s ADHD and ASD symptoms, and emotion regulation. Children completed a standardized executive functioning battery. Results indicated that 28% of parents and 53% of teachers rated children above the subclinical range on ASD symptoms. An interaction emerged such that higher ASD symptoms were only associated with poorer executive functioning for children with lower ADHD symptoms. However, ASD symptoms were predictive of poorer emotion regulation independent of ADHD symptoms. Findings revealed clinically significant ASD symptoms, which aided in explaining heterogeneity in self-regulation deficits.     

Relations Between Inhibition,Executive Functioning,and ADHD Symptoms: A Longitudinal Study from Age 5 to 8½ Years

The present study examined whether inhibition measured as early as preschool can predict more general executive functioning and ADHD symptoms at school age. In contrast to previous studies, the present study focused specifically on ADHD symptoms rather than general disruptive behavior problems, and boys and girls were studied separately. The main result was that inhibition was strongly related to ADHD symptoms both in school and at home for boys, but only in the school context for girls. Early inhibition was also significantly related to later executive functioning, and concurrent relations were found between executive functioning and ADHD symptoms, although in both cases only for boys. Besides this, inhibition added significantly to the variance, beyond that of executive functioning, which meant that for boys, inhibition and the other executive functioning explained about half the variance in inattention problems. The stronger relation between inhibition, executive functioning and ADHD symptoms for boys compared to girls could suggests that either the predictors of ADHD are different for the two sexes, or girls are more often equipped with some factor that protects them from developing ADHD symptoms, despite poor executive functioning. However, it is also possible that relations are just harder to demonstrate for girls due to their lower incidence of disruptive problem behaviors.     

Relations between inhibition, executive functioning, and ADHD symptoms: a longitudinal study from age 5 to 8(1/2) years.

The present study examined whether inhibition measured as early as preschool can predict more general executive functioning and ADHD symptoms at school age. In contrast to previous studies, the present study focused specifically on ADHD symptoms rather than general disruptive behavior problems, and boys and girls were studied separately. The main result was that inhibition was strongly related to ADHD symptoms both in school and at home for boys, but only in the school context for girls. Early inhibition was also significantly related to later executive functioning, and concurrent relations were found between executive functioning and ADHD symptoms, although in both cases only for boys. Besides this, inhibition added significantly to the variance, beyond that of executive functioning, which meant that for boys, inhibition and the other executive functioning explained about half the variance in inattention problems. The stronger relation between inhibition, executive functioning and ADHD symptoms for boys compared to girls could suggests that either the predictors of ADHD are different for the two sexes, or girls are more often equipped with some factor that protects them from developing ADHD symptoms, despite poor executive functioning. However, it is also possible that relations are just harder to demonstrate for girls due to their lower incidence of disruptive problem behaviors.     

Associations between respiratory sinus arrhythmia reactivity and internalizing and externalizing symptoms are emotion specific

Internalizing and externalizing disorders are often, though inconsistently in studies of young children, associated with low baseline levels of respiratory sinus arrhythmia (RSA). RSA is thus considered to reflect the capacity for flexible and regulated affective reactivity and a general propensity for psychopathology. However, studies assessing RSA reactivity to emotional challenges tend to report more consistent associations with internalizing than with externalizing disorders, although it is unclear whether this is a function of the type of emotion challenges used. In the present study, we examined whether baseline RSA was associated with internalizing and/or externalizing severity in a sample of 273 young children (ages 5–6) with elevated symptoms of psychopathology. Following motivation-based models of emotion, we also tested whether RSA reactivity during withdrawal-based (fear, sadness) and approach-based (happiness, anger) emotion inductions was differentially associated with internalizing and externalizing symptoms, respectively. Baseline RSA was not associated with externalizing or internalizing symptom severity. However, RSA reactivity to specific emotional challenges was associated differentially with each symptom domain. As expected, internalizing symptom severity was associated with greater RSA withdrawal (increased arousal) during fearful and sad film segments. Conversely, externalizing symptom severity was related to blunted RSA withdrawal during a happy film segment. The use of theoretically derived stimuli may be important in characterizing the nature of the deficits in emotion processing that differentiate the internalizing and externalizing domains of psychopathology.     

Predicting the Early Developmental Course of Symptoms of Attention Deficit Hyperactivity Disorder

Data from the National Institute of Child Health and Human Development Study of Early Child Care were examined to test whether: attention deficit/hyperactivity disorder (ADHD) symptoms remain stable from 54 months through early elementary school; behavioral inhibition and attention deficits assessed at 54 months predict ADHD symptoms in elementary school, even after controlling for their temporal stability; and early behavioral inhibition and attention deficits moderate the longitudinal stability in ADHD symptoms. Data were examined using continuous and categorical measures of symptoms. Modest stability in ADHD symptoms from 54 months to third grade was found. Measures of inhibition and inattention predicted later teacher ratings uniquely, but no evidence was found for moderation. Measures of preschool behavioral inhibition also predicted “persistently at risk status” defined by elevated teacher ratings over time. Results are discussed in terms of executive and motivational facets of inhibition that may be related to early signs of ADHD.     

Perceptuomotor functioning in preschool children with symptoms of attention deficit hyperactivity disorder

Given limited research on perceptual-motor functioning of preschool children with symptoms of ADHD, the purpose of this study was to compare the fine motor, gross motor, visuomotor, and oral-motor functioning of 49 4- to 6-yr.-old children with symptoms of Attention Deficit Hyperactivity Disorder and 48 typically developing children. Analysis showed scores of the ADHD group were significantly lower than those of the control group on all perceptuomotor measures. In addition, scores on all measures yielded significant correlations with scores on the Hyperactive-Inattentive scale of the Preschool Behavior Questionnaire. Regression analyses indicated that the scores of gross motor and visuomotor functioning were significant predictors of group classification (with and without ADHD). These findings extend the well documented findings of perceptuomotor deficits among school-age children with ADHD into the preschool period and emphasize the importance of early assessment and treatment of these deficits in young children with symptoms of ADHD.     

Cognitive deficits of executive functions and decision‐making in obsessive‐compulsive disorder

The nature of cognitive deficits in obsessive‐compulsive disorder (OCD) is characterized by contradictory findings in terms of specific neuropsychological deficits. Selective impairments have been suggested to involve visuospatial memory, set shifting, decision‐making and response inhibition. The aim of this study was to investigate cognitive deficits in decision‐making and executive functioning in OCD. It was hypothesized that the OCD patients would be less accurate in their responses compared to the healthy controls in rational decision‐making on a version of the Cambridge gambling task (CGT) and on the color‐word interference test and on a version of the Tower of Hanoi test (tower test) of executive functioning. Thirteen participants with OCD were compared to a group of healthy controls (n = 13) matched for age, gender, education and verbal IQ. Results revealed significant differences between the OCD group and the healthy control group on quality of decision‐making on the CGT and for achievement score on the tower test. On these two tasks the OCD group performed worse than the healthy control group. The symptom‐dimension analysis revealed performance differences where safety checking patients were impaired on the tower test compared to contamination patients. Results are discussed in the framework of cognition and emotion processing and findings implicate that OCD models should address, specifically, the interaction between cognition and emotion. Here the emotional disruption hypothesis is forwarded to account for the dysfunctional behaviors in OCD. Further implications regarding methodological and inhibitory factors affecting cognitive information processing are highlighted.     

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.     

Executive functioning deficits in relation to symptoms of ADHD and/or ODD in preschool children

The present study investigated the relation between executive functioning and symptoms of Attention‐Deficit/Hyperactivity Disorder (ADHD) and Oppositional Defiant Disorder (ODD) in children aged 4–6. A population‐based sample (n=201) was used and laboratory measures of inhibition, working memory and verbal fluency and teacher ratings of disruptive behaviour problems were collected. Both group differences and linear relations were studied and comorbidity was controlled for dimensionally. In both categorical and dimensional analyses, executive functioning was associated with symptoms of ADHD, but not with symptoms of ODD when controlling for comorbidity, and no significant interactive effects of ADHD and ODD symptoms were found. Effect sizes for significant effects were generally in the medium range. Regarding sex differences, the control for comorbid ODD symptoms appeared to affect the relation between ADHD symptoms and executive functioning somewhat more for girls compared with boys. In conclusion, poor executive functioning in preschool appears to be primarily related to symptoms of ADHD, whereas the relation to symptoms of ODD can be attributed to the large overlap between these two disruptive disorders. Copyright © 2006 John Wiley & Sons, Ltd.     

Are Elevations in ADHD Symptoms Associated with Physiological Reactivity and Emotion Dysregulation in Children?

The present study examined whether children with elevated attention-deficit/hyperactivity disorder (ADHD) symptoms display a unique pattern of emotion dysregulation as indexed by both parent report and physiological reactivity during experiences of failure. A sample of 61 children (9 to 13 years; M?=?11.62, SD?=?1.29; 48 % male) with and without clinical elevations in ADHD symptoms participated. Parent and teacher report of ADHD and oppositional defiant disorder (ODD) symptoms and parent report of internalizing problems were collected. Parents also provided ratings of children’s emotional negativity/lability and emotion regulation. Children’s physiological reactivity, based on changes in respiratory sinus arrhythmia (RSA) and skin conductance level (SCL), were assessed while they completed a manipulated social rejection task and impossible puzzle task. Regression analyses indicated that ADHD symptoms were associated with higher parent-rated emotional negativity/lability and with blunted RSA withdrawal in response to social rejection; these effects were not accounted for by co-occurring ODD symptoms or internalizing problems. ODD symptoms also were uniquely associated with parent ratings of poor emotion regulation. Internalizing problems were uniquely associated with emotional negativity/lability, poor emotion regulation, and increased SCL activity in response to social rejection. Results suggest that there may be a pattern of emotion dysregulation that is specific to ADHD symptomatology. The importance of contextual factors when examining physiological reactivity to stress in youth with ADHD is discussed.     

Does Childhood Executive Function Predict Adolescent Functional Outcomes in Girls with ADHD?

We prospectively followed an ethnically and socioeconomically diverse sample of preadolescent girls with ADHD (n = 140) and matched comparison girls (n = 88) over a period of 5 years, from middle childhood through early/mid-adolescence. Our aim was to examine the ability of measures of childhood executive function (EF) to predict functional outcomes in adolescence. Measures of neuropsychological functioning comprised the childhood predictors, with academic, social, and global functioning serving as adolescent criterion measures. Results indicated that childhood EF predicted (a) academic achievement and social functioning across our entire sample (independent of diagnostic group status) and (b) global functioning only in girls with ADHD (independent of IQ). These results highlight the non-specificity of EF deficits and suggest the importance of assessing and developing interventions that target EF impairments, particularly in those at high-risk for negative outcomes, in order to prevent long-term difficulties across a range of important functional domains.     

Early Fathering as a Predictor of Later Psychosocial Functioning Among Preschool Children with Behavior Problems

The present study examined the role of early fathering in subsequent trajectories of social emotional and academic functioning of preschool children with behavior problems. Participants were 128 preschool-aged children (73 boys, 55 girls) with behavior problems whose biological fathers took part in a longitudinal study. Children were 3 years of age at the beginning of the study and were assessed annually for 3 years. Early paternal depressive symptoms predicted many aspects of children’s outcome 3 years later, including externalizing and internalizing problems, social skills deficits, and lower cognitive and academic functioning, and predicted changes in children’s externalizing, internalizing, and social problems across the preschool years. Paternal socioeconomic status (SES) also consistently predicted children’s later functioning across these domains. Furthermore, self-reported paternal attention-deficit hyperactivity disorder (ADHD) symptoms and laxness, as well as observed frequent commands were associated with later externalizing problems in children. Paternal depressive symptoms and laxness mediated the relation between paternal ADHD symptoms and child functioning. Results suggest that aspects of early father functioning play an important role in the psychosocial, cognitive, and academic development of preschool-aged children with behavior problems.     

Severity of Children’s ADHD Symptoms and Parenting Stress: A Multiple Mediation Model of Self-Regulation

The goal of the current study was to determine the extent to which the perceived self-regulation deficits across behavioral, cognitive, and emotional domains seen in children with ADHD explain the association between the severity of ADHD symptoms and parenting stress. Participants for this study included 80 children (mean age = 10 years, 9 months) with a DSM-IV diagnosis of ADHD confirmed by a comprehensive clinical diagnostic assessment. Parents reported their own stress levels as well as the severity of their children’s ADHD symptoms, aggression, emotional lability, and executive functioning difficulties. Results indicated that the severity of children’s hyperactivity/impulsivity symptoms but not their inattention related to parenting stress. Multiple mediational analyses indicated that the association between hyperactivity/impulsivity and parenting stress was explained by children’s perceived comorbid aggression levels, emotional lability, and executive functioning difficulties. No significant differences in the strength of the mediators were found. The current study provides initial data showing that the perceived impairments in children’s self-regulation across emotional, cognitive, and behavioral domains are what parents report as stressful, not simply the severity of ADHD symptoms. Due to the cross-sectional nature of this study and shared variance from relying solely on parent report, it will be critical for future research to replicate our findings using longitudinal and multi-informant data such as teacher reports and standardized assessments.     

Are Sensation Seeking and Emotion Processing Related to or Distinct from Cognitive Control in Children with ADHD?

This study evaluated the relationship of (a) reactive inhibition and right-lateralized emotion processing to each other and (b) to executive control of response suppression, and (c) with regard to ADHD in 134 children ages 7–12 years. Reactive inhibition was indexed by child ratings of sensation seeking on the Sensation Seeking Scales, executive control by the Stop Signal Task, emotion processing by performance on the Chimeric Faces Test, and ADHD by parent- and teacher-reported symptoms. The results were consistent with a two-process model in which executive control, conceived as a right-hemisphere lateralized function, was distinct from sensation seeking and lateralized emotion processing. Supporting this distinction, ADHD was associated with executive control, but not with sensation seeking/reactive inhibition or lateralized emotion processing. The findings suggest that ADHD cannot be understood as a global right-lateralized neuropsychological weakness, but rather that it involves only particular functions that may be right lateralized. Findings further suggest that risk for comorbid disorders in ADHD (e.g., conduct disorder or mood disorders) may increase as a function of independent factors such as temperament. Mechanisms underlying executive inhibition and emotional processing could be functionally independent yet interact to multiply psychopathological risk in some children (leading, for example, to comorbid disorders).     

Are sluggish cognitive tempo symptoms associated with executive functioning in preschoolers?

The aim of this study is to investigate whether sluggish cognitive tempo (SCT) symptoms are associated with neurocognitive task performance and ratings of real-world executive functioning (EF) in preschoolers at risk for attention-deficit/hyperactivity disorder (ADHD). The associations between parent- and teacher-rated SCT symptoms and neuropsychological task performance and ratings of EF in 61 4-year-old preschool children (51 boys, 10 girls) with self-regulation difficulties were examined, with regression analyses controlling for the effects of ADHD inattention symptoms. In the study sample, higher teacher-rated SCT symptoms are significantly associated with poorer performance on tasks of visual-perceptual abilities, auditory and visual attention, sustained and selective attention, inhibitory control, pre-numerical/numerical concepts, and slower processing speed, but SCT symptoms are not significantly associated with working memory, attention shifting or cognitive flexibility when controlling for ADHD inattention. Higher parent-rated SCT symptoms are significantly associated with visual-perceptual abilities. ADHD inattention symptoms are more strongly associated than SCT with daily life EF ratings; neither parent- nor teacher-rated SCT symptoms are significantly associated with daily life ratings of inhibition, working memory, or planning/organization after controlling for ADHD inattention. This study suggests that SCT symptoms contribute to EF deficits at least on neurocognitive tasks assessing visual-perceptual/spatial abilities, attention to detail and processing speed, as observed in this sample of young children at risk for ADHD, and may be an important intervention target.