Direct assessment of the cognitive correlates of attention deficit disorders with and without hyperactivity

Evaluation of dental behavior, anxiety, fear, and its correlation with trait emotional intelligence in 8-12-year-old children: Exploring a new frontier in behavior modification

BACKGROUND

Children's fear and distress in dental settings often lead to anxiety and behavior issues. This study delves into why some children experience dental anxiety, whereas others do not, attributing differences to child-rearing and personality traits. Emotional intelligence (EQ), the ability to comprehend, generate, and manage emotions, is explored as a factor influencing a child's dental experience. This novel intelligence theory accommodates the intricacies of human-environment interactions.

AIM

The study aimed to investigate the relationship between EQ and a child's dental anxiety, fear, and behavior in children aged 8-12 years.

MATERIALS AND METHODS

The Trait Emotional Intelligence Questionnaire-Child Short Form, specifically developed for children aged between 8 and 12 years, was used among 100 participants reporting to the department outpatient department. The Frankl's Behavior Rating Scale, Modified Child Dental Anxiety Scale, and Children's Fear Survey Schedule-Dental Subscale were used to evaluate behavior, anxiety, and fear, respectively.

RESULTS

Results show a positive correlation between EQ and dental behavior (P = 0.002) whereas a negative correlation between EQ and dental anxiety and fear (P < 0.001).

CONCLUSION

This study sheds light on the intricate interplay between emotional intelligence, dental behavior, anxiety, and fear among children. By recognizing the impact of EQ, dental practitioners could adopt personalized strategies to alleviate anxiety and enhance cooperation, improving overall dental experiences for young patients.

Report of a Work Group on Sluggish Cognitive Tempo: Key Research Directions and a Consensus Change in Terminology to Cognitive Disengagement Syndrome

OBJECTIVE

The aim of this work was 2-fold: (1) to evaluate current knowledge and identify key directions in the study of sluggish cognitive tempo (SCT); and (2) to arrive at a consensus change in terminology for the construct that reflects the current science and may be more acceptable to researchers, clinicians, caregivers, and patients.

METHOD

An international Work Group was convened that, in early 2021, compiled an online archive of all research studies on SCT and summarized the current state of knowledge, noted methodological issues, and highlighted future directions, and met virtually on 10 occasions in 2021 to discuss these topics and terminology.

RESULTS

Major progress has been made over the last decade in advancing our understanding of SCT across the following domains of inquiry: construct measurement and stability; genetic, environmental, pathophysiologic, and neuropsychological correlates; comorbid conditions; functional impairments; and psychosocial and medication interventions. Findings across these domains are summarized, and potential avenues to pursue in the next generation of SCT-related research are proposed. Following repeated discussions on terminology, the Work Group selected "cognitive disengagement syndrome" (CDS) to replace "SCT" as the name for this construct. This term was deemed to best satisfy considerations that should apply when selecting terms for a condition or syndrome, as it does not overlap with established terms for other constructs, is not offensive, and reflects the current state of the science.

CONCLUSION

It is evident that CDS (SCT) has reached the threshold of recognition as a distinct syndrome. Much work remains to further clarify its nature (eg, transdiagnostic factor, separate disorder, diagnostic specifier), etiologies, demographic factors, relations to other psychopathologies, and linkages to specific domains of functional impairment. Investigators are needed with interests and expertise spanning basic, clinical, and translational research to advance our understanding and to improve the lives of individuals with this unique syndrome.

Could immersive daydreaming underlie a deficit in attention? The prevalence and characteristics of maladaptive daydreaming in individuals with attention-deficit/hyperactivity disorder

OBJECTIVE

Maladaptive daydreaming (MD) entails excessive immersion and engagement in complex fantasy worlds, causing distress and impairing functioning. Maladaptive Daydreamers often report that existing diagnostic labels are unhelpful for them. Previous studies reported high rates of comorbid attention deficit hyperactivity disorder (ADHD) among persons with MD, raising the question of their separateness. This study explored whether MD differs essentially from ADHD by examining an ADHD sample, hypothesizing a much lower incidence of MD.

METHOD

Adults diagnosed with ADHD (N = 83) were assessed for ADHD symptoms, MD, depression, loneliness, and self-esteem. Participants who exceeded the study's cutoff score for suspected MD were invited to participate in a structured diagnostic interview for MD.

RESULTS

In accordance with the hypothesis, only 20.5% of the ADHD sample met the proposed diagnostic criteria for MD. Compared with ADHD-only participants, this subgroup presented increased depression, loneliness, and lowered self-esteem.

CONCLUSION

MD has unique clinical characteristics that are distinct from ADHD. We suggest that in some cases presenting with ADHD symptoms, an MD conceptualization may better explain the clinical picture. Future research should aim at a better differentiation of daydreaming, ADHD, and related constructs such as mind-wandering.

Enhancing Executive Functions and Handwriting with a Concentrative Coordination Exercise in Children with ADHD: A Randomized Clinical Trial

Handwriting difficulties are common in children with Attention-Deficit/Hyperactivity Disorder (ADHD), and they have been associated with lower academic achievement and self-esteem. Our aim in this study was to determine if training coordination of the head, eyes, and arm and engaging in the necessary visual concentration associated with table tennis would improve executive functions and school-based handwriting among children with ADHD. We designed a randomized controlled trial to explore the therapeutic efficacy of this table tennis training and recruited 48 children with ADHD that we randomly assigned to one of three equal-sized training groups: (a) actual table tennis, (b) simulated table tennis (exergame), or (c) a control group receiving no additional training. The training intervention lasted 12-weeks in which the two different table tennis trainings (i.e., actual or simulated) were scheduled for three one-hour sessions per week. Outcome measures included a computerized handwriting evaluation, the Stroop test, and the Wisconsin Card Sorting Test (WCST). Participants in each table tennis training group showed significant improvements in handwriting performance, response time, and required time to achieve automation. Both intervention groups also showed significant improvements on the Stroop Color-Word test, but only the actual table tennis training group showed a significant improvement on the WCST. This study provided evidence of at least short-term improvements in executive functions and handwriting problems in children with ADHD through their participation in table tennis motor coordination activities.

Patterns of psychopathology and cognition in sex chromosome aneuploidy

Background

Sex chromosome aneuploidies (SCAs) are a collectively common family of genetic disorders that increase the risk for neuropsychiatric and cognitive impairment. Beyond being important medical disorders in their own right, SCAs also offer a unique naturally occurring model for studying X- and Y-chromosome influences on the human brain. However, it remains unclear if (i) different SCAs are associated with different profiles of psychopathology and (ii) the notable interindividual variation in psychopathology is related to co-occurring variation in cognitive ability.

Methods

We examined scores for 11 dimensions of psychopathology [Child/Adult Behavior Checklist (CBCL)] and general cognitive ability [full-scale IQ (FSIQ) from Wechsler tests] in 110 youth with varying SCAs (XXY = 41, XYY = 22, XXX = 27, XXYY = 20) and 131 typically developing controls (XX = 59, XY = 72).

Results

All SCAs were associated with elevated CBCL scores across several dimensions of psychopathology (two-sample t tests comparing the euploidic and aneuploidic groups [all |T| > 9, and p < 0.001]). Social and attentional functioning were particularly sensitive to the carriage of a supernumerary Y-chromosome. In particular, the XYY group evidenced significantly more social problems than both extra-X groups (Cohen’s d effect size > 0.5, Bonferroni corrected p < .05). There was marked variability in CBCL scores within each SCA group, which generally correlated negatively with IQ, but most strongly so for social and attentional difficulties (standardized β, − 0.3). These correlations showed subtle differences as a function of the SCA group and CBCL scale.

Conclusions

There is domain-specific variation in psychopathology across SCA groups and domain-specific correlation between psychopathology and IQ within SCAs. These findings (i) help to tailor clinical assessment of this common and impactful family of genetic disorders and (ii) suggest that dosage abnormalities of X- and Y-linked genes impart somewhat distinct profiles of neuropsychiatric risk.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11689-021-09407-9.

Sluggish Cognitive Tempo and Depressive Symptoms in Children and Adolescents Predict Adulthood Psychopathology

Sluggish cognitive tempo (SCT) is characterized by behavioral symptoms reflecting slowness and lethargy (e.g., sluggishness, appearing sleepy) and inconsistent alertness/mental confusion (e.g., daydreaming, fogginess). SCT is substantially correlated with the inattentive symptoms of attention-deficit/hyperactivity disorder (ADHD) and may be part of that domain, but in cross-sectional data, SCT is also strongly associated with both inattention and depression. To date, no study has examined the prospective associations of SCT symptoms in childhood/adolescence with symptoms of ADHD and internalizing problems in adulthood. Using a sample of 449 twin children and adolescent pairs, prospective multiple regression analyses examined whether self- and parent-reported SCT, depression, and parent-reported symptoms of ADHD predicted symptoms in adulthood 12 years later. SCT and depression at time one were strongly correlated (self-reported SCT and depression r = 0.84; parent-reported SCT and depression r = 0.78). When adult outcomes were separately regressed on each youth symptom dimension, self-reported SCT (β = 0.26, p < 0.0001) and depression (β = 0.13, p < 0.0001) each predicted adult symptoms of depression and self-reported SCT predicted inattention (β = 0.12, p = 0.0026). Parent-reported depression, but not parent-reported SCT, predicted self-reported adult depression symptoms (β = 0.17, p = 0.0003). In contrast, when each adult outcome was regressed simultaneously on youth self-reported SCT and depression, neither predicted adulthood inattention or depression. These findings indicate that SCT in childhood and adolescence is strongly associated concurrently and predictively with both inattention and depression. Theoretical and clinical applications of the construct of SCT must take its robust association with both inattention and depression into account.

Sluggish Cognitive Tempo, Internalizing Symptoms, and Executive Function in Adults With ADHD

OBJECTIVE

We sought to characterize relationships between sluggish cognitive tempo (SCT) and both internalizing symptoms and executive functioning in adults with ADHD.

METHOD

A total of 102 adults with ADHD completed clinical interviews and clinical rating scales. Hierarchical regression analyses were conducted to ascertain the independent predictive power of SCT symptoms for deficits in executive function (EF) after considering severity of ADHD inattentive and hyperactive-impulsive symptoms and internalizing symptoms.

RESULTS

SCT correlated with ADHD inattentive symptoms and dimensional measures of depression and anxiety but not with clinical diagnosis of depression or anxiety. SCT predicted EF deficits over and above the effects of internalizing and ADHD symptoms. This relationship between SCT and EF was limited to the subset of participants ( n = 48) receiving stimulant treatment.

CONCLUSION

SCT in adults with ADHD is associated with internalizing symptoms, ADHD inattentive symptoms, and, independently, with EF deficits. Further research is needed to ascertain why this relationship occurred primarily in adults concurrently receiving stimulants.

A Double Dissociation Between Inattentive and Impulsive Traits, on Tasks of Visual Processing and Emotion Regulation

OBJECTIVE

To dissociate between inattentive and impulsive traits common in attention deficit hyperactivity disorder (ADHD) using a non-dichotomous measurment of these traits.

METHOD

120 university students who completed the Conner's adult ADHD rating scales (CAARS) were also tested on the Microgenesis task which requires visual attention and on the Cyber Cruiser task which requires emotion regulation.

RESULTS

Results show that a measure of inattention was specifically related to a measure of effortful visual processing condition. In addition, a measure of impulsivity was specifically related to the tendency to fail in refueling one's car on time, although this relation was opposite to the predicted direction. Furthermore, by using exploratory and confirmatory factor analyses, the CAARS' factor structure was confirmed to be relevant to an Israeli population.

CONCLUSION

The current experiment supports the idea that visual attention may play a part in inattentive symptoms, and that emotion regulation may play a part in impulsivity symptoms.

Developmental Aspects of Sustained Attention among 2- to 6-year-old Children

This study examined sustained attention in children aged 2-6 years in two settings; during free play and during a structured test. Subjects were 48 nursery schoolchildren and 47 kindergarteners. In the free play setting, linear and quadratic relations with age were found for ability to sustain attention as measured by duration of play time and number of attended activities. Linear and quadratic relations were also found for distractibility as measured by the number of pauses in play. Older children tended to return to a previously attended activity following a break, whereas younger children did not. The ability to sustain attention increased until the age of 4 years, after which a plateau in development appeared. Results from the structured test showed no significant differences between age groups on the time spent attending to pictures, but revealed a significant linear trend for the ability to recall items from pictures. It is suggested that free play may be a sensitive measure of preschool-aged children’s ability to sustain attention.

Connectivity Analysis and Feature Classification in Attention Deficit Hyperactivity Disorder Sub-Types: A Task Functional Magnetic Resonance Imaging Study

Attention deficit hyperactivity disorder (ADHD) is a pervasive neuropsychiatric disorder. Patients with different ADHD subtypes show different behaviors under different stimuli and thus might require differential approaches to treatment. This study explores connectivity differences between ADHD subtypes and attempts to classify these subtypes based on neuroimaging features. A total of 34 patients (13 ADHD-IA and 21 ADHD-C subtypes) underwent functional magnetic resonance imaging (fMRI) with six task paradigms. Connectivity differences between ADHD subtypes were assessed for the whole brain in each task paradigm. Connectivity measures of the identified regions were used as features for the support vector machine classifier to distinguish between ADHD subtypes. The effectiveness of connectivity measures of the regions were tested by predicting ADHD-related Diagnostic and Statistical Manual of Mental Disorders (DSM) scores. Significant connectivity differences between ADHD subtypes were identified mainly in the frontal, cingulate, and parietal cortices and partially in the temporal, occipital cortices and cerebellum. Classifier accuracy for distinguishing between ADHD subtypes was 91.18 % for both gambling punishment and emotion task paradigms. Linear prediction under the two task paradigms showed significant correlation with DSM hyperactive/impulsive score. Our study identified important brain regions from connectivity analysis based on an fMRI paradigm using gambling punishment and emotion task paradigms. The regions and associated connectivity measures could serve as features to distinguish between ADHD subtypes.

The second attention disorder? Sluggish cognitive tempo vs. attention-deficit/hyperactivity disorder: update for clinicians

Sluggish cognitive tempo (SCT) refers to an impairment of attention in hypoactive-appearing individuals that first presents in childhood. At this time, it exists only as a research entity that has yet to debut in official diagnostic taxonomies. However, it seems likely that a constellation of characteristic features of SCT may form the criteria for a newly defined childhood disorder in the foreseeable future, provided limitations in the extant findings can be addressed by future research. Most clinicians who assess and treat cases of attention- deficit/hyperactivity disorder (ADHD) have likely seen and treated someone who falls within the parameters for SCT. This article outlines the history of SCT and reviews the current understanding of the disorder, how it is distinguishable from and similar to other attention disorders, and what future directions research and treatment may take. Based on this review and their clinical experience, the authors conjecture that SCT is probably distinct from ADHD rather than being an ADHD subtype, although there is notable overlap with the ADHD predominantly inattentive and combined presentations.

Effects of methylphenidate on acute math performance in children with attention-deficit hyperactivity disorder

OBJECTIVE

Examine the short-term (acute) effects of methylphenidate (MPH) on math performance in children with attention-deficit hyperactivity disorder (ADHD) and what factors predict improvement in math performance.

METHOD

One hundred ninety-eight children with ADHD participated in a double-blind, placebo-controlled, randomized crossover MPH trial. Math response to MPH was determined through administration of math problems adjusted to their academic level during the Restricted Academic Situation Scale (RASS). Student t tests were conducted to assess change in math performance with psychostimulants. Correlation between change on the RASS and change on the math performance was also examined. Linear regression was performed to determine predictor variables.

RESULTS

Children with ADHD improved significantly in their math with MPH (P < 0.001). The degree of improvement on the RASS (which evaluates motor activity and orientation to task) and on math performance on MPH was highly correlated. A child's age at baseline and Wechsler Individual Achievement Test (WIAT)-Numerical Operations standard scores at baseline accounted for 15% of variances for acute math improvement.

CONCLUSIONS

MPH improves acute math performance in children with ADHD. Younger children with lower math scores (as assessed by the WIAT) improved most on math scores when given psychostimulants.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00483106.

Objectively-measured impulsivity and attention-deficit/hyperactivity disorder (ADHD): testing competing predictions from the working memory and behavioral inhibition models of ADHD

Impulsivity is a hallmark of two of the three DSM-IV ADHD subtypes and is associated with myriad adverse outcomes. Limited research, however, is available concerning the mechanisms and processes that contribute to impulsive responding by children with ADHD. The current study tested predictions from two competing models of ADHD-working memory (WM) and behavioral inhibition (BI)-to examine the extent to which ADHD-related impulsive responding was attributable to model-specific mechanisms and processes. Children with ADHD (n = 21) and typically developing children (n = 20) completed laboratory tasks that provided WM (domain-general central executive [CE], phonological/visuospatial storage/rehearsal) and BI indices (stop-signal reaction time [SSRT], stop-signal delay, mean reaction time). These indices were examined as potential mediators of ADHD-related impulsive responding on two objective and diverse laboratory tasks used commonly to assess impulsive responding (CPT: continuous performance test; VMTS: visual match-to-sample). Bias-corrected, bootstrapped mediation analyses revealed that CE processes significantly attenuated between-group impulsivity differences, such that the initial large-magnitude impulsivity differences were no longer significant on either task after accounting for ADHD-related CE deficits. In contrast, SSRT partially mediated ADHD-related impulsive responding on the CPT but not VMTS. This partial attenuation was no longer significant after accounting for shared variance between CE and SSRT; CE continued to attenuate the ADHD-impulsivity relationship after accounting for SSRT. These findings add to the growing literature implicating CE deficits in core ADHD behavioral and functional impairments, and suggest that cognitive interventions targeting CE rather than storage/rehearsal or BI processes may hold greater promise for alleviating ADHD-related impairments.

The impact of emotional intelligence and intelligence quotient (IQ) on child anxiety and behavior in the dental setting

OBJECTIVE

The aim of this study was to evaluate the impact of IQ and EQ on child's anxiety and behavior in the dental setting.

MATERIALS AND METHODS

One hundred and seven children (age range 7-12 years) were selected. BarOn Emotional Quotient Inventory: Youth Version (Baron EQ-I: YV) and the Raven's Colored Progressive Matrices (RCPM) tests were administered on the first examination session. Children's anxiety and behavior were evaluated using the modified child dental anxiety scale (MCDAS) and the sound, eye and motor (SEM) scales, respectively, during the second session.

RESULTS

The mean (SD) age of subjects was 8.48 (1.41) years old. The result revealed a significant negative correlation between children's behavior and total EQ score (p < 0.01) but there was no relationship found between children's behavior and IQ score. A significant positive correlation was found between anxiety scores on MCDAS and SEM (p < 0.01), but no relationship was found between EQ and MCDAS scores. Both anxiety (p < 0.01) and EQ score (p < 0.01) were effective variables in predicting the child's SEM score.

CONCLUSION

The major finding of this research suggested that a high EQ may be more effective than a low EQ in moderating the level of cooperation during dental treatment of children. IQ scores, on the other hand, were related to the child's EQ score (r = 0.20) and age (r = - 0.29).

Biological and social influences on cognitive control processes dependent on prefrontal cortex

Cognitive control functions ("executive functions" [EFs] such as attentional control, self-regulation, working memory, and inhibition) that depend on prefrontal cortex (PFC) are critical for success in school and in life. Many children begin school lacking needed EF skills. Disturbances in EFs occur in many mental health disorders, such as ADHD and depression. This chapter addresses modulation of EFs by biology (genes and neurochemistry) and the environment (including school programs) with implications for clinical disorders and for education. Unusual properties of the prefrontal dopamine system contribute to PFC's vulnerability to environmental and genetic variations that have little effect elsewhere. EFs depend on a late-maturing brain region (PFC), yet they can be improved even in infants and preschoolers, without specialists or fancy equipment. Research shows that activities often squeezed out of school curricula (play, physical education, and the arts) rather than detracting from academic achievement help improve EFs and enhance academic outcomes. Such practices may also head off problems before they lead to diagnoses of EF impairments, including ADHD. Many issues are not simply education issues or health issues; they are both.

Academic performance in ADHD when controlled for comorbid learning disorders, family income, and parental education in Brazil

OBJECTIVE

Scholastic achievement in a nonclinical sample of ADHD children and adolescents was evaluated taking into consideration variables such as comorbid learning disorders, family income, and parental education which may also be associated with poor academic performance.

METHOD

After screening for ADHD in 396 students, the authors compared academic performance of 26 ADHD individuals and 31 controls paired for gender, age, and intelligence level considering both mathematics and Portuguese language scores. Learning disorders were investigated and the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV ) criteria were met using structured interviews.

RESULTS

The prevalence of academic underachievement was 2.98 times higher in students with ADHD, the most frequent subtype being predominantly inattentive. Parental educational level, family income, and comorbid learning disorders could not explain the discrepancies between ADHD students and controls.

CONCLUSIONS

ADHD seems to be associated with poor academic performance even in the absence of comorbid learning disorders, lower family income, and parental educational level.

Quantifying ADHD classroom inattentiveness, its moderators, and variability: a meta-analytic review

BACKGROUND

Most classroom observation studies have documented significant deficiencies in the classroom attention of children with attention-deficit/hyperactivity disorder (ADHD) compared to their typically developing peers. The magnitude of these differences, however, varies considerably and may be influenced by contextual, sampling, diagnostic, and observational differences.

METHODS

Meta-analysis of 23 between-group classroom observation studies using weighted regression, publication bias, goodness of fit, best case, and original metric analyses.

RESULTS

Across studies, a large effect size (ES = .73) was found prior to consideration of potential moderators. Weighted regression, best case, and original metric estimation indicate that this effect may be an underestimation of the classroom visual attention deficits of children with ADHD. Several methodological factors-classroom environment, sample characteristics, diagnostic procedures, and observational coding schema-differentially affect observed rates of classroom attentive behavior for children with ADHD and typically developing children. After accounting for these factors, children with ADHD were on-task approximately 75% of the time compared to 88% for their classroom peers (ES = 1.40). Children with ADHD were also more variable in their attentive behavior across studies.

CONCLUSIONS

The present study confirmed that children with ADHD exhibit deficient and more variable visual attending to required stimuli in classroom settings and provided an aggregate estimation of the magnitude of these deficits at the group level. It also demonstrated the impact of situational, sampling, diagnostic, and observational variables on observed rates of on-task behavior.

Subtypes of attention-deficit/hyperactivity disorder (ADHD): distinct or related disorders across measurement levels?

The aim of this literature review is to assess the current state of knowledge regarding differences and similarities between the inattentive (IA) and combined (C) subtypes of Attention-Deficit/Hyperactivity Disorder (ADHD) in order to detail challenges concerning further conceptualization, diagnostics, and treatment. The literature on ADHD-IA and ADHD-C was reviewed and contrasted across genetic, neuroanatomical, neurophysiological/ neurochemical, neuro(psycho)logical, and clinical psychiatric measurement levels. It was found that the more fundamental the measurement level, the less unambiguous evidence is found for subtype differences. Only on the clinical psychiatric diagnostic level, do more or less clear-cut differences in cognitive, social, academic, and behavioural functioning emerge. In conclusion, fundamental research that compares ADHD-IA and ADHD-C is relatively rare. At this point, only irrefutable phenomenological evidence of subtype differences seems to be available, even in attention problems which are presumed to be identical. The question as to whether both subtypes should be considered as two independent disorders was not adequately resolved.

Attentional functioning in children with ADHD - predominantly hyperactive-impulsive type and children with ADHD - combined type

Although particular importance has been attributed to attention deficits in attention deficit hyperactivity disorder (ADHD), there is no consensus as to the exact nature of inattention in ADHD or which components of attention are affected. The present study was based on a neuropsychological model of attention and assessed various components of attention in 23 children with ADHD/predominantly hyperactive-impulsive type (ADHD-H), 32 children with ADHD/combined type (ADHD-C) and healthy children (N(1) = 23 and N(2) = 32). A computerized test battery consisting of reaction time tasks of low complexity was used for the assessment of attention (alertness task, vigilance task, divided attention task, visual scanning task, incompatibility task, test of crossmodal integration, flexibility task). In comparison to healthy participants, patient groups were impaired in measures of vigilance, divided attention, selective attention and flexibility but not in measures of alertness. Analysis of the test performance of patient groups revealed no differences between children with ADHD-H and children with ADHD-C. The results of the present study suggest that both children with ADHD-H and children with ADHD-C are seriously impaired in attentional functioning. Children with ADHD-H and children with ADHD-C produced comparable results in measures of attention.

Attention-deficit disorder (attention-deficit/ hyperactivity disorder without hyperactivity): a neurobiologically and behaviorally distinct disorder from attention-deficit/hyperactivity disorder (with hyperactivity)

Most studies of attention-deficit/hyperactivity disorder (ADHD) have focused on the combined type and emphasized a core problem in response inhibition. It is proposed here that the core problem in the truly inattentive type of ADHD (not simply the subthreshold combined type) is in working memory. It is further proposed that laboratory measures, such as complex-span and dual-task dichotic listening tasks, can detect this. Children with the truly inattentive type of ADHD, rather than being distractible, may instead be easily bored, their problem being more in motivation (underarousal) than in inhibitory control. Much converging evidence points to a primary disturbance in the striatum (a frontal-striatal loop) in the combined type of ADHD. It is proposed here that the primary disturbance in truly inattentive-type ADHD (ADD) is in the cortex (a frontal-parietal loop). Finally, it is posited that these are not two different types of ADHD, but two different disorders with different cognitive and behavioral profiles, different patterns of comorbidities, different responses to medication, and different underlying neurobiologies.

Effects of methylphenidate on multiple components of attention in children with attention deficit hyperactivity disorder

RATIONALE

Methylphenidate (MPH) has been shown to be effective in the treatment of attention deficits in children with attention deficit hyperactivity disorder (ADHD). Although a variety of studies have been performed, there is little available information as to which components of attentional functioning are disturbed in ADHD.

OBJECTIVES

The aim of the present study was to monitor the effect of MPH on various measures of attention in children with ADHD.

METHODS

In a double-blind, placebo-controlled, crossover study, the attentional functioning of 58 children diagnosed with ADHD without psychiatric comorbidity was examined. Assessment of attention was performed on their usual MPH treatment and following withdrawal of the drug. Furthermore, the attentional performance of 58 healthy children was assessed. The test battery consisted of reaction time tasks, including measures of alertness, vigilance, divided attention, flexibility, and aspects of selective attention such as focused attention, inhibition, and integration of sensory information.

RESULTS

In comparison to the test performance of healthy children, children with ADHD displayed impairments of vigilance, divided attention, flexibility, and aspects of selective attention including focused attention, inhibition, and integration of sensory information. Statistical comparison of attentional functioning of children with ADHD on and off MPH treatment revealed that the medication resulted in an improved task accuracy regarding vigilance, divided attention, inhibition, focused attention, integration of sensory information, and flexibility.

CONCLUSION

The present findings indicate that various aspects of attention are markedly impaired in children with ADHD. Treatment with MPH was accompanied by improvements in attention functions of small to moderate sizes. Although MPH-induced improvements were observed in a broad range of attention measures, children with ADHD who were on MPH treatment nevertheless displayed serious deficits in a number of components of attention.

Applying a psychoeducational perspective to ADHD

This article examines whether various cognitive abilities are associated with symptoms of ADHD. Cognitive ability is conceptualized using Cattell-Horn-Carroll (CHC) theory as measured using the Woodcock-Johnson Tests of Cognitive Ability (3rd ed.). This article also examines whether test session behavior mediates the association between cognitive ability and ADHD. Participants are children ages 6 to 12 with (n= 33) and without (n= 19) ADHD. Results show that inattentive symptoms of ADHD are significantly related to the CHC ability of processing speed above and beyond the effect of test session behavior. Symptoms of ADHD (both inattention and hyperactivity/impulsivity) are also significantly associated with visual spatial processing, but this is completely mediated by test session behavior. It is concluded that inattentive symptoms of ADHD are associated with slower processing speed and that this relationship is not explained by test session behavior.

Sensory-motor deficits in children with developmental coordination disorder, attention deficit hyperactivity disorder and autistic disorder

Children who have been diagnosed with any one developmental disorder are very likely to meet diagnostic criteria for some other developmental disorder. Although comorbidity has long been acknowledged in childhood disorders, little is understood about the mechanisms that are responsible for the high level of comorbidity. In a series of studies, we have investigated the link between sensory-motor deficits and developmental disorders. Poor sensory-motor integration has long been implicated as a cause of motor problems in developmental disorders such as developmental coordination disorder (DCD), and our recent research has also investigated sensory-motor deficits in children with attention deficit hyperactivity disorder (ADHD) and autistic disorder. Based on a critical examination of relevant literature and some of our recent research findings, we argue that the importance of poor sensory-motor functioning in discriminating children with different disorders has been underestimated. Poor sensory-motor coordination appears to be linked to DCD, but not ADHD. Also, sensory-motor deficits in children with DCD and autistic disorder may provide insight into some of the social difficulties found in these groups of children. This research will increase our understanding of why children with one developmental disorder typically also have problems in other areas.

Timing is everything: executive functions in children exposed to elevated levels of phenylalanine

This study addresses how the timing of a known biological insult affects the developmental progression of executive functions. The sample consisted of children exposed to elevated levels of phenylalanine, either postnatally, as in phenylketonuria (PKU; n = 46), or prenatally, as in maternal PKU (n = 15). Nonhyperphenylanemic siblings of children with PKU (n = 18) served as controls. Results indicated that elevated levels of phenylalanine are toxic to the neurological systems that manage executive functions and cognitive tempo. This toxicity is dose dependent, with higher levels of phenylalanine being more detrimental. Executive function difficulties noted in PKU are consistent with attention deficit hyperactivity disorder (ADHD)-inattentive type, whereas maternal PKU offspring had executive function difficulties consistent with ADHD-combined type.

Neuropsychological performance in DSM-IV ADHD subtypes: an exploratory study with untreated adolescents

OBJECTIVE

To explore neuropsychological performance in untreated Brazilian adolescents suffering from attention-deficit hyperactivity disorder (ADHD).

METHOD

We assessed 30 untreated adolescents with ADHD and 60 healthy control subjects, aged 12 to 16 years, using a neuropsychological battery including the Wisconsin Card-Sorting Test (WCST), the Stroop Test (ST), the Digit Span, and the Word Span.

RESULTS

We found neuropsychological differences among the DSM-IV ADHD subtypes. Adolescents with the predominantly inattentive subtype (ADHD-I) performed more poorly than did control subjects on both the Digit Span and the ST. On both the Digit Span and the WCST, adolescents with the combined subtype (ADHD-C) presented significantly more impairments than did control subjects. Adolescents with the predominantly hyperactive-impulsive type (ADHD-HI) did not differ significantly from the control subjects in any measure assessed, but had a better performance than did those with ADHD-C on both the Digit Span and the WCST. In addition, adolescents with ADHD-HI performed better on the ST than did adolescents with ADHD-I.

CONCLUSIONS

These findings suggest cognitive differences among ADHD subtypes, supporting the diagnostic distinction among them. Adolescents with ADHD-HI do not seem to have significant cognitive deficits.

Inattentive behavior in childhood: epidemiology and implications for development

Poor concentration is a relatively common childhood problem. The current North American psychiatric diagnostic classification system (Diagnostic and Statistical Manual of Mental Disorders, fourth edition; DSM-IV), American Psychological Association, 1994) differentiates children whose problems are distinguished primarily by symptoms of inattention (ADHD-I) from those whose difficulties are characterized by overactive, impulsive behavior by providing various subtypes within a broad diagnostic category. Yet, comparatively little is known about children who exhibit purely inattentive behavior. This study aims to redress this issue by using a large, community-based, epidemiological sample of 7-year-old children to compare the developmental functioning, social, and environmental backgrounds of children with pure inattentive behavior to that of children with pure overactive behavior and combined problems of inattentive and overactive behavior. Five hypotheses, centered on the validity of distinguishing inattentive behavior from overactivity, are tested. Children with pure inattentive behavior were more likely to have general cognitive delays, particularly in the area of language development, and were more likely to come from a family in which the father was of low occupational status. The results are discussed in relation to the implications for research and the identification of needs and intervention with children who exhibit pure inattentive behavior.

An intervention approach for children with teacher- and parent-identified attentional difficulties

Using a multimodal and multi-informant method for diagnosis, we selected 33 children by teacher and parent nomination for attention and work completion problems that met DSM-IV criteria for attention-deficit/hyperactivity disorder (ADHD). Of the 33 children in this group, 21 participated in the initial intervention, and 12 were placed in an ADHD control group and received the intervention after pre- and posttesting. A similarly selected group of 21 children without difficulties in attention and work completion served as a control group. Each child was assessed on pre- and posttest measures of visual and auditory attention. After an 18-week intervention period that included attention and problem-solving training, all children in the intervention and control groups were retested on visual and auditory tasks. Children in both ADHD groups showed significantly poorer initial performance on the visual attention task. Whereas the ADHD intervention group showed commensurate performance to the nondisabled control group after training, the ADHD control group did not show significant improvement over the same period. Auditory attention was poorer compared to the control group for both ADHD groups initially and improved only for the ADHD intervention group. These findings are discussed as a possible intervention for children with difficulties in strategy selection in a classroom setting.

Arithmetic disabilities and ADD subtypes: implications for DSM-IV

This study investigated whether specific academic deficits were associated with attention-deficit disorder (ADD) subtypes. Twenty students (ages 8-12) with attention-deficit disorder with hyperactivity (ADD/H) were compared to 20 students with attention-deficit disorder without hyperactivity (ADD/noH). Group differences were compared using a MANCOVA, and paired t tests were used to compare within-group differences. Dependent variables for the within-group differences were four achievement subtest scores from the Woodcock-Johnson Psycho-Educational Battery-Revised: Letter-Word Identification, Passage Comprehension, Calculation, and Applied Problems. Consistent with much of the previous research, no significant between-group differences were found on the achievement measures. Significant differences did, however, appear in the six within-group comparisons, all involving lower performance on the Math Calculations subtest. For students with ADD/H, only one comparison (with Math Applied Problems) reached significance. Students with ADD/noH, however, had significantly lower scores on the Calculation subtest compared to all of the other achievement subtests. These results provided additional support for the hypothesis that inattention exerts a specific and deleterious effect on the acquisition of arithmetic computation skills. These findings have important implications for the diagnosis and treatment of ADHD as conceptualized in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Association, 1994), because they suggest that students with ADHD-Predominantly Inattentive Type may be at increased risk for arithmetic calculation deficits.

Components of attention in children with complex partial seizures with and without ADHD

PURPOSE

To evaluate attentional difficulties in children with complex partial seizures, we reviewed the records of 12 children with complex partial seizures with attention deficient hyperactivity disorder (CPS/ADHD); 21 children with CPS without ADHD (CPS); 22 children with ADHD; and 15 control children.

METHODS

Each child completed a computerized performance test (CPT), which evaluated sustained attention, inhibition of response, response time, and consistency of response. The ADHD groups also completed the CPT after a dose of methylphenidate.

RESULTS

The results found poorest performance on the CPT by the CPS/ADHD group. Particular difficulty in attention was found for children with epilepsy regardless of the ADHD diagnosis. When methylphenidate was administered to the ADHD groups, both groups improved in performance on the CPT.

CONCLUSIONS

Epilepsy may predispose children to attention problems that can significantly interfere with learning. Similar improvement for children with CPS/ADHD was found with methylphenidate compared with baseline as for children with ADHD but without CPS.

Executive dysfunctions in children with attention deficit hyperactivity disorder

One hundred and twenty-four male children ranging in age from seven to 12 years-old were selected. The sample was divided into two groups: (1) sixty-two with attention deficit hyperactivity disorder (ADHD) children; and (2) sixty-two normal matched controls (N-ADHD). Three tests were individually administered: (1) Wisconsin Card Sorting Test (WCST); (2) Verbal fluency and semantics (animals and fruits); and, (3) Picture Arrangement subtest of the WISC-R. For all the test scores, statistically significant differences were found between both ADHD and N-ADHD groups. Two separate factor analyses were performed, using the normal and ADHD groups. Four factors were found for the N-ADHD group, which accounted for 85.7% of the variance. The factor structure presented some similarities in both groups: Factor 2, 3 and 4 in the control group corresponded to factors 1, 2 and 3 in the ADHD group. Nonetheless, in the ADHD group Factor 1 (Abstraction and Flexibility Factor) was absent. Results are interpreted as supporting the hypothesis of executive dysfunction in children with ADHD.

Academic underachievement in ADHD subtypes

Although a relationship between attention-deficit/hyperactivity disorder (ADHD) and academic underachievement has been widely reported, the nature of this relationship has not been specified. The present investigation addresses this relationship directly by comparing 24 students (20 males and 4 females) with ADHD and 20 students (15 males and 5 females) with attention-deficit disorder without hyperactivity (ADD/noH) referred to a university-based diagnostic clinic for comprehensive neuropsychological assessment. The students ranged in age from 6 years 0 months to 12 years 10 months. Consistent with previous reports, this study found that math achievement test scores for students with ADD/noH were significantly lower than those for students with ADHD. These findings support previous research suggesting the ADD/noH may represent a distinct ADD subtype. It is hypothesized that inattention interferes with students' ability to master abstract symbol systems, especially in the acquisition of basic arithmetic skills in the primary grades.

Relation between intelligence and psychopathology among preschoolers

Examined the relation between intelligence and psychopathology in a nonclinical sample of 510 children ages 2 to 5 years. Psychopathology was measured using both quantitative, dimensional methods (Child Behavior Checklist [CBCL]) and taxonomic methods (the Diagnostic and Statistical Manual of Mental Disorders [3rd. ed., Rev.; DSM-III-R; American Psychological Association, 1987]). IQ scores were derived from either the McCarthy Scales of Children's Abilities or the Bayley Scales of Mental Development. Based on quantitative, dimensional data, results support similar findings among older children and clinical populations that lower McCarthy general, verbal, and perceptual-performance IQ scores are associated with various types of psychopathology. Results were also consistent for the DSM-III-R data. Bayley IQ scores did not predict CBCL psychopathology or DSM-III-R Disruptive Disorders, but they did predict the presence of a DSM-III-R diagnosis. Early identification of intellectual deficits among preschoolers ages 3 to 5 may help to prevent later school difficulties and severe psychopathology.

Reading and spelling deficits among children attending a psychiatric day treatment program

To investigate the specific behavioural and cognitive characteristics which may account for academic deficits in children with psychiatric disorders, 50 children admitted to a day treatment and school program were assessed using behaviour questionnaires for parents and teachers, and tests assessing intelligence (WISC-R), language (CELF-R) and academic performance (Kaufman Test of Educational Achievement). The academic measures Reading Decoding, Reading Comprehension and Spelling formed the dependent variables. Behaviour and cognitive measures which distinguished the sample from normative data constituted the independent variables. Hierarchical multiple regression analyses were performed in order to identify behaviour and cognitive measures accounting for the academic deficits. In the analyses, three measures (Digit Span, Sentence Assembly, Recalling Sentences), probably assessing overlapping cognitive/linguistic functions, accounted for a large proportion of variance for Reading Decoding (0.47), Reading Comprehension (0.63) and Spelling (0.29). None of the behaviour measures accounted for any variance of the academic variables. It is argued that linguistic dysfunction is a primary deficit which underlies problems in academic learning.

Distractibility in hyperactive and conduct-disordered children

Hyperactive children are often said to be inattentive and distractible. However, the results from a number of experimental studies are equivocal. To examine this discrepancy, a Chinese version of the Stroop Test was devised. Four groups of subjects recruited from a community sample of 1479 Chinese boys living in Hong Kong took part in the investigation. These were: (1) a pure hyperactive (HA) group; (2) a mixed hyperactive/conduct-disordered (HA + CD) group; (3) a pure conduct-disordered (CD) group; and (4) a normal (N) control group. The results revealed that HA children were more markedly affected by the introduction of distracting stimuli. This distractibility was probably a function of both stimulus potency and the random order in which stimuli were presented. The specificity of a greater distractibility to HA children indicates its diagnostic value with regard to hyperactivity. The failure to find a similar deficit in HA + CD children raises questions about the clinical identity of this mixed diagnostic group.

Validity of DSM-IV ADHD predominantly inattentive and combined types: relationship to previous DSM diagnoses/subtype differences

Since 1980, three different diagnostic nomenclatures have been published regarding attention-deficit hyperactivity disorder (ADHD). These changing conceptualizations and diagnostic criteria have generated considerable confusion.

OBJECTIVE

To examine the multidimensional DSM-IV ADHD criteria in relation to how children and adolescents with a previous DSM-III ADD diagnosis or a DSM-III-R ADHD diagnosis are diagnosed according to DSM-IV criteria.

METHOD

Children whose original diagnoses were according to DSM-III and DSM-III-R criteria received retrospective diagnoses according to DSM-IV criteria.

RESULTS

Predominantly inattentive (n = 30) and combined types (n = 26) were compared on their previous DSM-III and DSM-III-R diagnoses and on demographic, behavioral, cognitive, and comorbidity variables. Predominantly inattentive and combined type diagnoses corresponded with DSM-III ADD/WO and ADD/H diagnoses, respectively. The DSM-III-R ADHD diagnosis did not correspond with either DSM-IV subtype. Children with the combined type diagnosis had more externalizing codiagnoses, and their parents reported more externalizing, delinquent, and aggressive behaviors. Children with the predominantly inattentive type had more math learning disability codiagnoses.

CONCLUSION

Results support a multidimensional conceptualization of ADHD. There exists close correspondence between the DSM-III ADD/WO type and the DSM-IV predominantly inattentive type and between the DSM-III ADD/H type and the DSM-IV combined type.

External Validity of Attention Deficit Disorder without Hyperactivity: A Review of the Evidence

The research evidence for the external validity of Attention Deficit Disorder without Hyperactivity as separate from Attention Deficit Disorder with Hyperactivity is examined. The history of the association between these two diagnoses is summarized, as is the clinical significance of examining this issue. Research on the behavioral characteristics, family history, psychiatric comorbidity, test performance, treatment response, physiological and neuroanatomical correlates of these two groups is reviewed. It is concluded that the evidence supporting the external validity of Attention Deficit Disorder without Hyperactivity as a distinct clinical entity is lacking, although psychophysiological research is emerging as a promising area of research in this regard.

Congruence of behavioral symptomatology in children with ADD/H, ADD/WO, and learning disabilities

Although evidence generally supports the behavioral differentiation of attention deficit disorder with hyperactivity (ADD/H) and attention deficit disorder without hyperactivity (ADD/WO), a growing body of literature suggests that children with learning disabilities (LD) share behavioral symptomatology with children diagnosed as having ADD/WO. The present study examined this issue by comparing parent and teacher behavioral ratings among groups of children diagnosed as having ADD/H, ADD/WO, and LD on symptoms of impulsivity, inattention, and social withdrawal. The subjects were 77 outpatients in a diagnostic and referral-service clinic who were divided into three groups. Group 1 included children with a primary diagnosis of ADD/H (n = 35), Group 2 included children with a primary diagnosis of ADD/WO (n = 25), and Group 3 included children with a primary diagnosis of learning disabilities (n = 17). The results indicated that parents and teachers view children with ADD/H as more disruptive than children with ADD/WO or LD. Children with ADD/WO or LD were described as more underactive and shy and as daydreaming more often than children with ADD/H. Teachers rated children with ADD/WO and LD as being similar to each other on symptoms of withdrawal and impulsivity, but both parents and teachers endorsed different symptoms of inattention for children with ADD/WO or LD. Issues related to comorbidity and differentiation of behavioral symptomatology are discussed.

Occurrence and pattern of impaired reading and written language in children with attention deficit disorders

The purpose of this study was to investigate the occurrence and severity of reading, spelling, and written language impairment in children clinically referred for Attention Deficit Hyperactivity Disorder (ADHD). Specific questions involved 1) whether ADD subgroups with and without hyperactivity differ in reading, spelling, and written language achievement, 2) whether age and gender interact with ADD sub-group class to affect reading/written language achievement, and 3) whether prevalence of impaired reading/written language in these subgroups is consistent with previous reports in heterogeneous samples. Subjects were 115 ADD children aged 6-12 who were subclassified as ADD + H(72 percent) and ADD - H(28 percent) by objective teacher ratings. Dependent measures included tests of single word recognition and vocabulary, word attack, contextual comprehension, written spelling, written sentence construction, and writing fluency, in addition to a structured behavioral observation, during which aspects of inattention and motor activity were coded. A large fraction of this sample met public school LD criteria (54 percent), and achievement on most measures was globally poorer than the respective test normative groups. The ADD + H subgroup showed significantly poorer word attack skills, while the subgroups did not significantly differ from each other on other reading/written language measures. However, 17 percent of the total ADD sample were ≥ 1.5 SD below the mean in total reading achievement, and 29 percent were ≥ 1.5 SD below the mean on measures of written spelling/language. Gender X age interactions, indicating poorer performance in the middle age group of females, were likely related to lower IQ.