Early concurrent and longitudinal symptoms of ADHD and ODD: relations to different types of inhibitory control and working memory

BACKGROUND: The aim of the present study was to investigate how three different types of inhibitory control - interference control within task, interference control outside task, and prepotent response inhibition - and two types of working memory - verbal and spatial - would relate to early symptoms of attention deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD), both concurrently and longitudinally. METHODS: Seventy-two preschoolers, 1/3 who had been identified as being at risk for developing ADHD and/or ODD, completed neuropsychological tasks designed to measure inhibitory control and working memory. Behavioral symptoms were measured through parental and teacher ratings of the DSM-IV criteria for ADHD and ODD. RESULTS: Our results suggest distinct types of inhibitory control as being good predictors of concurrent and longitudinal symptoms of ADHD, rather than ODD. However, no associations were obtained between working memory and ADHD or ODD symptoms either concurrently or longitudinally. CONCLUSIONS: This study emphasizes the need to isolate complex executive processes and break them down into components in order to properly understand the neuropsychological roots involved in ADHD and ODD.     

Task-related default mode network modulation and inhibitory control in ADHD: effects of motivation and methylphenidate

Background: Deficits characteristic of attention deficit/hyperactivity disorder (ADHD), including poor attention and inhibitory control, are at least partially alleviated by factors that increase engagement of attention, suggesting a hypodopaminergic reward deficit. Lapses of attention are associated with attenuated deactivation of the default mode network (DMN), a distributed brain system normally deactivated during tasks requiring attention to the external world. Task‐related DMN deactivation has been shown to be attenuated in ADHD relative to controls. We hypothesised that motivational incentives to balance speed against restraint would increase task engagement during an inhibitory control task, enhancing DMN deactivation in ADHD. We also hypothesised that methylphenidate, an indirect dopamine agonist, would tend to normalise abnormal patterns of DMN deactivation. Method: We obtained functional magnetic resonance images from 18 methylphenidate‐responsive children with ADHD (DSM‐IV combined subtype) and 18 pairwise‐matched typically developing children aged 9–15 years while they performed a paced Go/No‐go task. We manipulated motivational incentive to balance response speed against inhibitory control, and tested children with ADHD both on and off methylphenidate. Results: When children with ADHD were off‐methylphenidate and task incentive was low, event‐related DMN deactivation was significantly attenuated compared to controls, but the two groups did not differ under high motivational incentives. The modulation of DMN deactivation by incentive in the children with ADHD, off‐methylphenidate, was statistically significant, and significantly greater than in typically developing children. When children with ADHD were on‐methylphenidate, motivational modulation of event‐related DMN deactivation was abolished, and no attenuation relative to their typically developing peers was apparent in either motivational condition. Conclusions: During an inhibitory control task, children with ADHD exhibit a raised motivational threshold at which task‐relevant stimuli become sufficiently salient to deactivate the DMN. Treatment with methylphenidate normalises this threshold, rendering their pattern of task‐related DMN deactivation indistinguishable from that of typically developing children.     

The course of neuropsychological functions in children with attention deficit hyperactivity disorder from late childhood to early adolescence

OBJECTIVE: The aim of this follow-up study was to investigate the course of performance in attentional tasks in children with ADHD and normal controls in late childhood and preadolescence over short periods of time. The development of two dimensions of attention was compared: alertness/arousal and inhibitory control. METHOD: Children with ADHD (N=28) and normal controls (N=25) were examined at three times: at baseline (age mean=10.8 years, SD=1.5), after one year (age mean=12.0 years, SD=1.6), and after 2.6 years (age mean=13.3 years, SD=1.6). They performed two tasks of a computerized battery for attentional performance: Alertness--a test of simple reaction time to visual stimuli contrasting a condition with and without auditory warning signal, and Incompatibility--a test of spatial interference/inhibitory control. Clinical diagnosis according to DSM-III-R criteria was established at time 1 and time 3 by structured diagnostic interviews. RESULTS: In the Alertness task significant group differences regarding increased reaction time variability in ADHD, but not for reaction time itself, were found at time 1 and more pronounced at time 2. At time 3 group differences had disappeared. In the Incompatibility task group differences in number of errors were not observed at time 1, whereas children with ADHD made significantly more errors at time 2 and less pronounced at time 3. The degree of clinical symptom remission after 2.6 years was not related to changes in neuropsychological performance. CONCLUSION: When measuring attentional functions, the selection of an appropriate time window seems to be essential for the detection of group differences between ADHD children and controls, because group differences are most pronounced before adolescence. The different developmental course of selective components of attention should be taken into account.     

Early developmental precursors of impulsive and inattentive behavior: from infancy to middle childhood

BACKGROUND: We examined infancy and toddler-age precursors of impulsivity and inattention in school-age children. Children (50 boys, 39 girls) had been participants since infancy in the Bloomington Longitudinal Study. METHOD: Individual differences in children's self-regulatory competence were assessed at 8 years of age, using laboratory tests and observations of three central constructs: Inhibitory Control, Behavioral Control, and Attentional Disengagement. RESULTS: We found that measures of caregiver-child interaction, child temperament, and child cognitive competence during the toddler period significantly predicted variations in children's later impulsive functioning. However, the strength of these relationships, and the type and combination of significant risk factors, were differentially patterned in relation to specific subtypes of later child impulsivity. CONCLUSIONS: These data provide further evidence for the multidimensional nature of child impulsivity, and they highlight the importance of examining toddler-age precursors of children's later self-regulatory competence.     

What's in a game: the effect of social motivation on interference control in boys with ADHD and autism spectrum disorders

Background:  Children with attention deficit hyperactivity disorder (ADHD) and with autism spectrum disorders (ASD) are known to have cognitive control deficits. Some studies suggest that such deficits may be reduced when motivation is increased through tangible reinforcers. Whether these deficits can also be modulated by non-tangible reinforcers has hardly been studied.
Methods:  Therefore, the effect of social motivation on the ability to suppress irrelevant information (i.e., interference control) was investigated in 22 ADHD boys, 22 ASD boys, and 33 typically developing (TD) boys. An adapted Eriksen Flanker task was administered under a motivational condition in which the boys were told that they were competing with peers, and under a neutral condition in which standard instructions were given.
Results:  In comparison with TD boys, boys with ADHD were impaired even when no interference was present, while this was not the case for the ASD boys. All groups benefited from the motivation manipulation, i.e., their performance increased when they thought they were competing with peers. Although the boys with ADHD were still slower than TD boys when motivated, they performed as accurately as TD boys. Children with ASD also improved slightly in accuracy and response speed, but this did not reach significance.
Conclusion:  Children with ADHD are able to exert sufficient cognitive control when they are motivated, which is in line with the current models of ADHD. However, motivation seems to have a general effect on performance and is not solely related to cognitive control abilities. In contrast, this effect was not obtained in children with ASD.     

The influence of sex on the course and psychiatric correlates of ADHD from childhood to adolescence: A longitudinal study

Background: Little is known about the influence of sex on the course of attention‐deficit/hyperactivity disorder (ADHD) and its comorbid psychiatric conditions. The purpose of this study was to examine the effect of sex on the course and psychiatric correlates of ADHD from childhood into adolescence. Methods: Two identically designed, longitudinal, case–control family studies of male and female probands with and without ADHD and their siblings were combined. All subjects were blindly assessed with structured diagnostic interviews. Among subjects with a lifetime history of ADHD (n = 471, mean age 11.5 ± 4.3 years at baseline), we used linear growth curve models to estimate the effect of time on the change in ADHD symptoms, and whether this effect differed by sex. We also we examined the effect of sex on the association between ADHD and the longitudinal progression of comorbid psychopathology using structural equation models. Results: We found no evidence that sex moderated the effect of age on ADHD symptoms; in both genders, age exhibited a similar effect on the decline of ADHD symptoms. However, the female sample demonstrated greater stability in comorbid psychopathology from childhood into adolescence. Furthermore, we found that the stability of comorbid psychopathology in females remained significant after accounting for the correlation between adolescent psychopathology and adolescent ADHD. In males, childhood and adolescent comorbid psychopathology were no longer correlated when adolescent ADHD was taken into account. Conclusions: Our findings indicate that while the course of ADHD across childhood and adolescence did not differ between males and females, patterns of psychiatric comorbidity were conditional on sex. Future studies should explicitly test how sex modifies the associations between ADHD and risk factors and ADHD and associated functional outcomes.     

Explaining the relationship between temperament and symptoms of psychiatric disorders from preschool to middle childhood: hybrid fixed and random effects models of Norwegian and Spanish children

Background

Four explanations for the concurrent and prospective associations between temperament and psychopathology in children have been suggested: predisposition, complication/scar, common cause/continuity, and pathoplasty/exacerbation. Because the confounding effects of common causes have not been ruled out in prior work, the support for the various explanations is uncertain.

Methods

Screen‐stratified community samples of 4‐year olds in Trondheim, Norway (n = 1,042), and 3‐year olds in Barcelona, Spain (n = 622), were assessed biennially for symptoms of attention‐deficit/hyperactivity (ADHD), oppositional defiant (ODD), conduct (CD), anxiety, and depressive disorders through interviewer‐based psychiatric interviews across four waves of data collection. The parents completed child temperament ratings. The data were analyzed with random and fixed effects regression adjusted for all time‐invariant unmeasured confounders (e.g., genetics, common methods bias, item overlap).

Results

In both Norway and Spain and across ages, negative affect predisposed children to symptoms of all disorders except CD, low effortful control predisposed children to ADHD and ODD‐symptoms, and surgency predisposed children to increased ADHD‐symptoms. Complication effects were observed in the Spanish children for ADHD‐symptoms, which increased surgency and diminished effortful control, and for ODD‐symptoms, which decreased surgency. The common cause and pathoplasty/exacerbation explanations were not supported.

Conclusions

The present results are consistent with the view that temperament plays a causal role in the development of symptoms of psychiatric disorders in children. Because temperament is malleable, interventions targeting the affective, attentional, and behavioral regulatory components of temperament may reduce psychopathology in children.     

Parenting and the development of conduct disorder and hyperactive symptoms in childhood: a prospective longitudinal study from 2 months to 8 years

BACKGROUND: This study investigated the early processes involved in the development of symptoms of conduct disorder and hyperactivity. METHOD: The study employed a prospective design, over a period from 2 months to 8 years. Detailed observational data of early and later mother-child interactions were collected, infant prefrontal function (the A not B task) was assessed, and symptoms of child conduct disorder and hyperactivity were rated by maternal report at age 5 and 8 years. RESULTS: The principal findings of the study were that emotional dysregulation on the A not B task at 9 months predicted symptoms of conduct disorder at 5 and 8 years, and delayed object reaching times on the same task predicted hyperactive symptoms at 5 years. These two developmental trajectories were associated with distinct patterns of early parenting that were strongly influenced by infant gender. Thus, in boys early emotional dysregulation was predicted by rejecting and coercive parenting, and delayed reaching on the A not B task by coercive parenting, whereas in girls only continuity from earlier infant behaviour could be demonstrated. There was strong continuity between these early infant behaviours and later child disturbance that was partially mediated by parenting for conduct disorder symptoms (maternal hostile parenting in boys, and maternal coercive parenting in girls), but not for hyperactive symptoms. CONCLUSIONS: These data would suggest that only in boys was there evidence for the existence of a sensitive period for the development of hyperactive symptoms, and to a lesser extent, conduct disorder symptoms.     

Developmental trajectories of depressive symptoms from early childhood to late adolescence: gender differences and adult outcome

BACKGROUND: Limited information is available on gender differences and young-adult poor outcome in children and adolescents following distinct developmental trajectories of depressive symptoms. METHODS: Parent information on depressive symptoms of 4- to 18-year-olds from an ongoing Dutch community-based longitudinal multiple-cohort study (N = 2,076) was used to estimate trajectories from semi-parametric mixture models. The identified trajectories were used to predict depressive problems, general mental health problems, referral to mental health care, and educational attainment in young adulthood. RESULTS: In both genders six distinct developmental trajectories were identified. Gender differences existed not only in level, but also in shape and timing of onset of depressive problems. Only in girls was a chronic trajectory of early childhood-onset depression identified. In both boys and girls a group with increasing levels of depressive symptoms was identified that reached a high level around adolescence, although boys showed an earlier onset. Two decreasing trajectories were found in boys, one reaching normative levels of depressive symptoms around late childhood and one around mid-adolescence, while none was found for girls. Individuals who followed elevated trajectories during their whole childhood or starting at adolescence had significantly more depressive and other mental health problems in young adulthood compared to those who followed normative trajectories. Boys in these elevated trajectories showed lower educational attainment, while girls were more likely to have been referred to mental health care. CONCLUSIONS: This study shows the value of estimating growth-mixture models separately for boys and girls. Girls with early childhood or adolescence-onset depressive problems and boys with depressive problems during childhood or starting in adolescence are especially at risk for poor outcome as young adults and should be considered candidates for intervention.     

The influence of maternal socioeconomic and emotional factors on infant weight gain and weight faltering (failure to thrive): data from a prospective birth cohort

Aims

To study the influence of maternal socioeconomic and emotional factors on infant weight gain and weight faltering (failure to thrive) in the first year of life.

Methods

The Gateshead Millennium Baby Study is a population birth cohort in northeast England studied prospectively from birth, via parental questionnaires and a health check aged 13 months. Data were collected on maternal education, deprivation, eating attitudes, and depression, using the Edinburgh Post Natal Depression Scale (EPDS) at 3 months. Weight gain was assessed using change in weight SD score, conditional on birth weight (Thrive Index); weight faltering was defined as conditional weight gain below the 5th centile.

Results

Of 923 eligible infants born at term, 774 (84%) had both weight and questionnaire data. Replicating a previous finding, both the highest and the lowest levels of deprivation were associated with weight faltering; this was independent of the type of milk feeding. No relation was found with maternal educational status. Maternal eating restraint was unrelated to weight gain. Infants of mothers with high depression symptom scores (EPDS >12) had significantly slower weight gain and increased rates of weight faltering up to 4 months (relative risk 2.5), especially if they came from deprived families, but by 12 months they were no different from the remainder of the cohort.

Conclusions

In this setting, social and maternal characteristics had little influence on infants'' weight gain, apart from a strong, but transient effect of postnatal depression.