Predictors and Moderators of Treatment Outcome in Cognitive Training for Children With ADHD.

Objective: To explore whether clinical variables and initial cognitive abilities predict or moderate (far) transfer treatment outcomes of cognitive training. Method: A total of 98 children (aged 8-12 years) with ADHD were randomly assigned to Cogmed Working Memory Training or a new cognitive training called "Paying Attention in Class." Outcome measures included neurocognitive assessment, parent and teacher rated questionnaires of executive functioning behavior and academic performance. Predictor/moderator variables included use of medication, comorbidity, subtype of ADHD, and initial verbal and visual working memory skills. Results: Parent and teacher ratings of executive functioning behavior were predicted and moderated by subtype of ADHD. Word reading accuracy was predicted by subtype of ADHD and comorbidity. Use of medication and initial verbal and visual spatial working memory skills only predicted and moderated near transfer measures. Conclusion: Cognitive training can be beneficial for certain subgroups of children with ADHD; individual differences should be taken into account in future trials.

Interventions to improve executive functioning and working memory in school-aged children with AD(H)D: a randomised controlled trial and stepped-care approach.

BACKGROUND: Deficits in executive functioning are of great significance in attention-deficit/hyperactivity disorder (ADHD). One of these executive functions, working memory, plays an important role in academic performance and is often seen as the core deficit of this disorder. There are indications that working memory problems and academic performance can be improved by school-oriented interventions but this has not yet been studied systematically. In this study we will determine the short- and long-term effects of a working memory--and an executive function training applied in a school situation for children with AD(H)D, taking individual characteristics, the level of impairment and costs (stepped-care approach) into account. METHODS/DESIGN: The study consists of two parts: the first part is a randomised controlled trial with school-aged children (8-12 yrs) with AD(H)D. Two groups (each n = 50) will be randomly assigned to a well studied computerized working memory training 'Cogmed', or to the 'Paying attention in class' intervention which is an experimental school-based executive function training. Children will be selected from regular -and special education primary schools in the region of Amsterdam, the Netherlands. The second part of the study will determine which specific characteristics are related to non-response of the 'Paying attention in class' intervention. School-aged children (8-12 yrs) with AD(H)D will follow the experimental school-based executive function training 'Paying attention in class' (n = 175). Academic performance and neurocognitive functioning (primary outcomes) are assessed before, directly after and 6 months after training. Secondary outcome measures are: behaviour in class, behaviour problems and quality of life. DISCUSSION: So far, there is limited but promising evidence that working memory - and other executive function interventions can improve academic performance. Little is know about the applicability and generalization effects of these interventions in a classroom situation. This study will contribute to this lack of information, especially information related to real classroom and academic situations. By taking into account the costs of both interventions, level of impairment and individual characteristics of the child (stepped-care approach) we will be able to address treatment more adequately for each individual in the future. TRIAL REGISTRATION: Nederlands Trial Register NTR3415.

The use of health care services and psychotropic medication in a community sample of 9-year-old schoolchildren with ADHD.

OBJECTIVE: To examine the prevalence of the use of health care services and psychotropic medication within a community sample (N = 283) of 9-year-old school children and, more specifically, to evaluate the use of prescribed stimulants. METHODS: Data from the second follow-up phase of the "Study of Attention Deficit Maastricht" (SAM) were analysed. Assessments at age 9 included a structured psychiatric interview with parents, behaviour and family situation questionnaire, IQ estimate and global assessment scale. Use of health care services and medication was obtained by the DICA-R and from the Youth Health Care records. RESULTS: About 190 children of the selected sample had at least one child psychiatric diagnosis, 26 (14%) of them were clinically referred and 12 (6%) received stimulants. Of the children with ADHD (N = 45), 10/45 (22%) received stimulants. Conversely, 2 out of 12 children who were treated with stimulants did not meet full DSM-IV diagnostic criteria, but were subthreshold ADHD cases. The treatment status was highly dependent on being clinically referred. CONCLUSION: The major finding of our survey is a lack of referral to child mental health services, and associated underdiagnosis and undertreatment, particularly in children with ADHD. There is a critical need to translate and implement the diagnostic and treatment guidelines to clinical practice.

Relation between cognitive and motor performance in 5- to 6-year-old children: results from a large-scale cross-sectional study.

The relation between cognitive and motor performance was studied in a sample of 378 children aged 5-6. Half of these children had no behavior problems; the others were selected for externalizing (38%) or internalizing problems (12%). Quantitative and qualitative aspects of motor performance were related to several aspects of cognition, after controlling for the influence of attention. No relation between global aspects of cognitive and motor performance was found. Specific positive relations were found between both aspects of motor performance, visual motor integration and working memory, and between quantitative aspects of motor performance and fluency. These findings reveal interesting parallels between normal cognitive and motor development in 5- to 6-year-old children that cannot be ascribed to attention processes.

Speed, speed variability, and accuracy of information processing in 5 to 6-year-old children at risk of ADHD.

The early assessment of Attention-Deficit/Hyperactivity Disorder (ADHD) children has mainly focused on the behavioral, social, and pre-academic impairments. This study examined whether 5 to 6-year-old children at risk of ADHD are characterized by information-processing deficits. By screening 1317 children in Southern Limburg (the Netherlands) with the Child Behavior Checklist, 363 were selected and underwent a computerized examination. Eighteen months later, standardized psychiatric information was obtained. Thirty-three ADHD children were compared with 75 borderline ADHD children, 122 pathological controls, and 133 healthy controls. ADHD and borderline ADHD children were slower and more variable in their processing speed on all tasks than children with no or other pathology. These differences were most pronounced for the divided and focused attention tasks. Furthermore, one measure of a state regulation deficit discriminated between groups. With regard to accuracy, only the proportion of misses on a go-no-go task was higher in the ADHD group than in the other groups. Evidence was found that ADHD is better seen as a continuum rather than a discrete category. Already at a young age, children at risk of ADHD show specific information-processing deficits. Deficits in time perception and/or energetic state control in children with ADHD may possibly account for subnormal task performance.

Reliability and validity of a qualitative and quantitative motor test for 5- to 6-year-old children.

Clumsiness in preschool children may be a precursor to impaired academic performance and psychological and developmental problems. It is assumed that in this age group especially the qualitative aspects (=pattern) of a movement reflect variations in motor development. Currently available motor tests for this age group, however, mostly objectify quantitative aspects of a movement alone and do not objectify qualitative aspects. The aim of this study was to develop a new, valid, and reliable tool (Maastricht's Motor Test (MMT)) to objectify qualitative and quantitative aspects of movement in 5- to 6-year-old children. The test covers Static Balance (14 items), Dynamic Balance (20 items), Ball Skills (eight items), and Diadochokinesis and Manual Dexterity (28 items). About 50% of the items measure qualitative aspects and 50% quantitative aspects of movements. In total 487 subjects were recruited from the first year of primary school. To validate the test, one school doctor's global judgment was used as a form of expert validity. Sensitivity and specificity were calculated for different cut-off points. Intra-class correlation coefficients (ICC) of inter-rater (N = 42), intra-rater (N = 24), and test-retest (N = 43) agreement were determined. ICCs of the qualitative total score ranged from 0.61 to 0.95 and were comparable with those of the total quantitative score. The MMT can be used to objectify both qualitative and quantitative aspects of movements. The additional value of the qualitative observations has to be determined in children with various developmental problems.

Low- and high-level controlled processing in executive motor control tasks in 5-6-year-old children at risk of ADHD.

BACKGROUND: The scant research on the characteristics of Attention-Deficit/Hyperactivity Disorder (ADHD) in kindergarten years curtails progress on early assessment of ADHD. METHOD: By screening a general population sample of 1317 five- to six-year-old children, four groups of children were selected. The performance of 30 children later diagnosed with ADHD was compared with 74 children later diagnosed with 'borderline ADHD' (children exhibiting all ADHD symptoms but without disruptions on two situations), 113 children later diagnosed with other psychopathology, and 126 healthy controls on computerised motor control tasks involving low- and high-level controlled processing. In addition, motor control was compared with movement speed. RESULTS: The children at risk of ADHD were in general less accurate and more variable in their movements than the children with other psychopathology and healthy controls. Under conditions of high-level controlled processing, the children at risk of ADHD were disproportionately more inaccurate and had a more unstable performance with their preferred hand than the other children. In addition, linear effects were found, with the children at risk of ADHD having the worst performance, followed by the children with 'borderline ADHD', and then both groups of control children. No significant group differences were found in movement speed. CONCLUSIONS: The main findings are interpreted as evidence for a specific deficit in high-level controlled processing in young children at risk of ADHD, now found in a motor task, rather than a response task. Furthermore, the results support the notion that ADHD represents a dimensional trait. In addition, problems in movement control (the need to allocate attentional capacity) rather than problems in movement speed distinguish children at risk of ADHD from other children. The findings are interpreted as evidence that higher-order executive processes, such as self-control and self-regulation, are already affected early in the development of ADHD.

Neurocognitive performance of 5- and 6-year-old children who met criteria for attention deficit/hyperactivity disorder at 18 months follow-up: results from a prospective population study.

The aim of this prospective study was to examine whether neurocognitive performance of children aged 5-6 years distinguished children who were later diagnosed with attention deficit/hyperactivity disorder(ADHD) or "borderline ADHD" from children without ADHD after adjustment for behavioral measures and to examine the influence of comorbid psychopathology. Out of a general population of 1,317 children, 366 children were selected on the basis of their scores on the Child Behavior Checklist (CBCL). Eighteen months later, the parents were interviewed using a standardized child psychiatric interview: 33 children were classified as ADHD and 75 children as borderline ADHD, and there were 258 children without ADHD. Children with rated ADHD were significantly impaired on measures of visuomotor ability and working memory compared to children without ADHD after adjustment for CBCL results. The performance of borderline ADHD children was in between that of children with and without ADHD. In addition, 4 groups of children were analyzed: 9 ADHD, 24 ADHD with comorbid oppositional defiant disorder/conduct disorder (ODD/CD), 59 ODD/CD, and 274 controls. Children with rated comorbid ADHD and ODD/CD performed significantly worse on these tasks compared to children with rated ODD/CD and control children while they did not differ from ADHD children. Our results imply that neurocognitive measures can contribute to the early identification of ADHD with and without comorbid ODD/CD.

Quality of movement as predictor of ADHD: results from a prospective population study in 5- and 6-year-old children.

The aims of this prospective study were (1) to examine whether quantitative and/or qualitative aspects of motor performance in 5- to 6-year-old children can predict attention-deficit-hyperactivity disorder (ADHD) 18 months later; (2) to investigate whether this relation is also present in oppositional defiant disorder and conduct disorder (ODD/CD). Quantitative and qualitative aspects of motor performance were tested in a selected community sample (n=401; 232 males, 169 females; mean age 6 years 4 months, SD 6 months, range 5 years 4 months to 7 years 11 months) using the Maastricht Motor Test. Eighteen months later, standardized psychiatric information was obtained with the Amsterdam Diagnostic Interview for Children and Adolescents: 35 children were classified as having ADHD, and 92 children as having ODD/CD. Weighted analyses were used in logistic regression analyses to investigate predictive values. Unlike quantitative aspects of motor performance, qualitative aspects were predictive of ADHD. Motor performance was not predictive of ODD/CD.

A longitudinal community study: do psychosocial risk factors and child behavior checklist scores at 5 years of age predict psychiatric diagnoses at a later age?

OBJECTIVE: To examine the extent to which certain risk factors in 5- to 6-year-old children predict later psychopathology in a population-based sample of children from the province of Limburg in the south of the Netherlands. METHOD: Of the 2,290 children of interest, 1,317 children were screened with the Child Behavior Checklist (CBCL) and psychosocial risk factors for these children were collected. On the basis of the CBCL ratings, 403 children participated in the second stage in which, 1.5 years later, standardized child psychiatric information was obtained. Weighted logistic regression analyses were used to investigate predictors of psychopathology. RESULTS: In separate analyses of specific types of child psychopathology, different risk factors emerged as significant. Low-level parental occupation and having foreign-born parents were predictive of conduct disorders, and living in a single-parent family and a having a life event were the most important predictors of mood and anxiety disorders. Furthermore, CBCL-based ratings at 5 to 6 years of age corresponded well with interview-defined diagnoses 1.5 years later. CONCLUSIONS: Investigation of psychosocial risk factors and CBCL scores at the age of 5 to 6 years could be helpful in predicting child psychopathology and could help identify children at risk, in order to provide them with timely attention.