Instability of the DSM-IV Subtypes of ADHD from preschool through elementary school

Prevalence of probable Attention-Deficit/Hyperactivity Disorder symptoms: result from a Spanish sample of children

Background

The aims of our study were to: (i) determine the prevalence of children aged 4 to 6 years with probable Attention-Deficit/Hyperactivity Disorder (ADHD) symptoms in the Spanish population; and (ii) analyse the association of probable ADHD symptoms with sex, age, type of school, origin (native or foreign) and socio-economic status in these children.

Methods

This cross-sectional study included 1189 children (4 to 6 years-old) from 21 primary schools in 19 towns from the Ciudad Real and Cuenca provinces, Castilla-La Mancha region, Spain. The ADHD Rating Scales IV for parents and teachers was administered to determine the probability of ADHD. The 90th percentile cut-off was used to establish the prevalence of inattention, hyperactivity/impulsivity and combined subtype.

Results

The prevalence of children with probable ADHD symptoms was 5.4% (2.6% inattention subtype symptoms, 1.5% hyperactivity/impulsivity subtype symptoms, and 1.3% combined subtype symptoms). Children aged 4 to 5 years showed a higher prevalence of probable ADHD in the inattention subtype symptoms and in total of all subtypes than children aged 6 years, and children with low socio-economic status reported a higher prevalence of probable ADHD symptoms (each subtype and total of all of them) than those with medium and high socio-economic status.

Conclusions

Early diagnosis and an understanding of the predictors of being probable ADHD are needed to direct appropriate identification and intervention efforts. These screening efforts should be especially addressed to vulnerable groups, particularly low socio-economic status families and younger children.

Comorbid symptoms of inattention, autism, and executive cognition in youth with putative genetic risk

BACKGROUND

Symptoms of autism spectrum disorder (ASD) and inattention (IA) are highly comorbid and associated with deficits in executive cognition. Cognitive deficits have been posited as candidate endophenotypes of psychiatric traits, but few studies have conceptualized cognitive deficits as psychiatric comorbidities. The latter model is consistent with a latent factor reflecting broader liability to neuropsychological dysfunction, and explains heterogeneity in the cognitive profile of individuals with ASD and IA.

METHODS

We tested competing models of covariance among symptoms of ASD, IA, and cognition in a sample of 73 youth with a known genetic mutation.

RESULTS

A common executive factor fit best as a cognitive comorbidity, rather than endophenotype, of the shared variance between measures of IA and ASD symptoms. Known genetic risk explained a third of the shared variance among psychiatric and cognitive measures.

CONCLUSIONS

Comorbid symptoms of ASD, IA, and cognitive deficits are likely influenced by common neurogenetic factors. Known genetic risk in ASD may inform future investigation of putative genetic causes of IA.

How neuropsychology can inform our understanding of preschool ADHD: Clinical and research implications

Neuropsychological assessments in preschoolers have not received as much attention as in older children and adults. Attention-deficit/hyperactivity disorder (ADHD) is a common disorder that occurs in early childhood associated with poor academic and personal outcomes, such as learning and social difficulties. Preschoolers with ADHD may present cognitive deficits that are related with the ADHD symptoms of inattention, hyperactivity, and impulsivity, but may also interfere, beyond and above the ADHD symptoms, with everyday functioning. Most importantly, cognitive deficits in preschoolers seem to predict future ADHD symptoms. Yet, the practice of neuropsychological assessment in this age-group has been limited. The present selective review highlights the contribution of comprehensive neuropsychological assessments to the early identification of symptomatic preschoolers and to our understanding of the nature and developmental trajectory of ADHD.

ADHD Prevalence in Spanish Preschoolers: Comorbidity, Socio-Demographic Factors, and Functional Consequences

OBJECTIVE

The object was to examine the prevalence of ADHD among preschoolers, analyzing comorbidity, and the association with socio-demographic factors.

METHOD

We conducted a two-phase epidemiological study of 1,104 preschoolers aged 3 to 6 years in Catalonia, Spain. The Early Childhood Inventory-4 (ECI-4) was administered to parents and teachers. Children at risk of ADHD were assessed using open-ended face-to-face interviews and were observed in a school setting. ADHD diagnoses were based on Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria.

RESULTS

The prevalence of ADHD diagnosis was 5.4%. Male sex and first-born status were risk factors for ADHD. Parents reported more symptoms (12.9%) than teachers (8.7%). Behavioral problems (odds ratio [OR] = 12, p = .001), autism spectrum disorder problems (OR = 9.5, p = .001), and obsessive-compulsive problems and tics (OR = 5.9, p = .001) were specifically related to ADHD diagnosis. Mother's health status and school achievement were lower in ADHD children.

CONCLUSION

Even at early stages of development, ADHD has high rates of comorbidity and a significant impact on school performance and family health.

Maternal obesity and attention-related symptoms in the preterm offspring

BACKGROUND

Maternal pre-pregnancy obesity, in term-born children, is associated with an increased risk of attention problems, however this relationship has not been explored among children born extremely preterm.

AIM

To estimate the risk of attention problems at age 10years in children born very preterm to overweight (i.e., body mass index (BMI) 25-29kg/m²) and obese (i.e., BMI≥30kg/m²) women relative to the risk among children born to women who were neither overweight nor obese (i.e. BMI<25kg/m²).

STUDY DESIGN

Multi-center prospective cohort study.

METHODS

A total of 764 children born before the 28th week of gestation and whose mother's pre-pregnancy height and pre-pregnancy weight were obtained at birth had an IQ≥70 at age 10years when parents and teachers completed Child Symptom Inventory-4 questionnaires that included items about the presence of ADHD.

RESULTS

Compared to children whose mother's pre-pregnancy weight was in the normal range (BMI<25kg/m²), children were at increased risk of parent-identified ADHD behaviors if their mother was overweight (odds ratio (OR)=1.9; 95% confidence interval (CI): 1.1, 3.3), or obese (OR=2.3; 95% CI: 1.4, 3.9). They were not at increased risk of teacher-identified ADHD characteristics if their mother was overweight before her pregnancy (OR=1.0; 95% CI: 0.6, 1.8), or obese (OR=1.0; 95% CI: 0.6, 1.6).

CONCLUSION

Maternal overweight and obesity are associated with increased risk of parent-identified ADHD characteristics at 10years of age in children born extremely preterm.

Impulsivity Symptoms as Core to the Developmental Externalizing Spectrum

Impulsivity is posited to be a key part of the externalizing spectrum during childhood, but this idea has received minimal empirical attention. The goal of the present investigation was to utilize network analysis to determine whether behavioral impulsivity symptoms are key components of the externalizing network across several developmental periods from preschool into adolescence. Participants were 109 preschoolers (64 % male) ages 3 to 6, 237 children (59 % male) ages 6 to 9, 372 children (59 % male) ages 10 to 13, and 357 adolescents (59 % male) ages 13 to 17 and their parents. Parents completed ratings of Attention-Deficit/Hyperactivity Disorder (ADHD) and Oppositional Defiant Disorder (ODD) symptoms on a well-validated rating scale. Network analyses indicated that ADHD and ODD were somewhat differentiated in preschool, becoming united by behavioral impulsivity symptoms during early childhood, and then differentiating into inattention versus externalizing clusters later during childhood and in adolescence. Behavioral impulsivity symptoms were core to the externalizing spectrum across most developmental periods, but core inattentive and ODD symptoms were also identified in line with progressive differentiation. These results suggest the increasing importance of impulsivity symptoms across development, explaining externalizing comorbidity and potentially serving as a viable target for childhood interventions for externalizing problems.

How Persistent is ADHD into Adulthood? Informant Report and Diagnostic Thresholds in a Female Sample

The persistence of attention-deficit/hyperactivity disorder (ADHD) into adulthood, particularly in women, is an unresolved question. Using a diverse, prospectively followed female sample (ADHD: n = 140; comparison: n = 88), we examined (a) informant (parent- vs. self-report) and (b) symptom threshold (DSM-IV cutoffs vs. a developmentally referenced criterion [DRC]) with respect to estimates of ADHD persistence into young adulthood (M = 19.6 years). We also ascertained the linkages of ADHD status (as measured by each informant and via the different symptom cutoffs) with impairment in key outcome domains. Informant diagnostic concordance was significant but small (κ = 0.22). Via parent report, more childhood-ascertained probands (44 %) than comparison participants (1 %) met full ADHD criteria in adulthood (p < 0.001, ϕ = 0.47); parallel results were found via self-report (22 % vs. 2 %; p < 0.001, ϕ = 0.28). As expected, DRC designations yielded higher persistence estimates than DSM cutoffs. With control of key covariates, parent-reported ADHD was independently associated with poor outcomes on eight of nine measures but self-reported ADHD was associated only with low math scores. Also, participants who met the DRC cutoff but not the higher DSM threshold showed similar impairment to DSM-diagnosed participants, far greater than that of participants who met neither cutoff. A lowered symptom threshold in adulthood compared to childhood appears justified.

Systemic Inflammation during the First Postnatal Month and the Risk of Attention Deficit Hyperactivity Disorder Characteristics among 10 year-old Children Born Extremely Preterm

Although multiple sources link inflammation with attention difficulties, the only human study that evaluated the relationship between systemic inflammation and attention problems assessed attention at age 2 years. Parent and/or teacher completion of the Childhood Symptom Inventory-4 (CSI-4) provided information about characteristics that screen for attention deficit hyperactive disorder (ADHD) among 793 10-year-old children born before the 28th week of gestation who had an IQ ≥ 70. The concentrations of 27 proteins in blood spots obtained during the first postnatal month were measured. 151 children with ADHD behaviors were identified by parent report, while 128 children were identified by teacher report. Top-quartile concentrations of IL-6R, TNF-α, IL-8, VEGF, VEFG-R1, and VEGF-R2 on multiple days were associated with increased risk of ADHD symptoms as assessed by a teacher. Some of this increased risk was modulated by top-quartile concentrations of IL-6R, RANTES, EPO, NT-4, BDNF, bFGF, IGF-1, PIGF, Ang-1, and Ang-2. Systemic inflammation during the first postnatal month among children born extremely preterm appears to increase the risk of teacher-identified ADHD characteristics, and high concentrations of proteins with neurotrophic properties appear capable of modulating this increased risk.

Managing childhood and adolescent attention-deficit/hyperactivity disorder (ADHD) with exercise: A systematic review

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is one of the most common neuropsychiatric disorders affecting some 8-10% of children worldwide. Increasing research has shed light on the life course of the disorder, suggesting that majority of children with ADHD will continue to have persistent symptoms into adulthood. The mainstay of ADHD management has been pharmacologic and behavioural/psychological interventions, with little attention paid to exercise as a potential management strategy. A systematic review, examining both the short-term and long-term effects of exercise on children with ADHD, is timely and necessary to guide further research in this area.

METHODS

Using the keywords [exercise OR physical OR activity OR sport] AND [attention deficit hyperactivity disorder OR ADHD OR ADDH], a preliminary search on the PubMed and Ovid database yielded 613 papers published in English between 1-Jan-1980 and 1-July-2016. Full articles were also reviewed for references of interest.

RESULTS

A total of 30 studies were included in this systematic review. Both short-term and long-term studies support the clinical benefits of physical activity for individuals with ADHD. Cognitive, behavioural and physical symptoms of ADHD were alleviated in most instances, and the largest intervention effects were reported for mixed exercise programs. No adverse effects arising from physical exercise were reported in any of the studies, suggesting that exercise is a well-tolerated intervention.

CONCLUSION

Physical activity, in particular moderate-to-intense aerobic exercise, is a beneficial and well-tolerated intervention for children and adolescents with ADHD. Future research should include more adequately-powered trials and investigate the ideal exercise prescription.

Heterogeneity in development of aspects of working memory predicts longitudinal attention deficit hyperactivity disorder symptom change

The role of cognitive mechanisms in the clinical course of neurodevelopmental disorders is poorly understood. Attention Deficit Hyperactivity Disorder (ADHD) is emblematic in that numerous alterations in cognitive development are apparent, yet how they relate to changes in symptom expression with age is unclear. To resolve the role of cognitive mechanisms in ADHD, a developmental perspective that takes into account expected within-group heterogeneity is needed.

METHOD

The current study uses an accelerated longitudinal design and latent trajectory growth mixture models in a sample of children ages 7-13 years carefully characterized as with (n = 437) and without (n = 297) ADHD to (a) identify heterogeneous developmental trajectories for response inhibition, visual spatial working memory maintenance, and delayed reward discounting and (b) to assess the relationships between these cognitive trajectories and ADHD symptom change.

RESULTS

Best-fitting models indicated multiple trajectory classes in both the ADHD and typically developing samples, as well as distinct relationships between each cognitive process and ADHD symptom change. Developmental change in response inhibition and delayed reward discounting were unrelated to ADHD symptom change, while individual differences in the rate of visual spatial working memory maintenance improvement predicted symptom remission in ADHD.

CONCLUSION

Characterizing heterogeneity in cognitive development will be crucial for clarifying mechanisms of symptom persistence and recovery. Results here suggest working memory maintenance may be uniquely related to ADHD symptom improvement. (PsycINFO Database Record

Co-Occurrence of ODD and CD in Preschool Children With Symptoms of ADHD

OBJECTIVE

Patterns of co-occurrence between ADHD, Oppositional Defiant Disorder (ODD), and Conduct Disorder (CD) were examined in a sample of non-referred preschool children. ADHD subtypes and sex differences were also explored.

METHOD

Children aged 3.5 years ( n = 1,048) with high scores on ADHD characteristics were recruited from the Norwegian Mother and Child Cohort Study and clinically assessed, including a semi-structured psychiatric interview.

RESULTS

In children with ADHD, concurrent ODD was present more often than CD (31% vs. 10%), but having ADHD gave higher increase in the odds of CD than of ODD (ODD: odds ratio [OR] = 6.7, 95% confidence interval [CI] = [4.2, 10.8]; CD: OR = 17.6, 95% CI = [5.9, 52.9]). We found a greater proportion of children having the combined ADHD subtype as well as more severe inattentiveness among children with co-occurring CD compared with ODD. Sex differences were minor.

CONCLUSION

There are important differences in co-occurring patterns of ODD and CD in preschool children with ADHD.

Evaluating relationships among clinical working memory assessment and inattentive and hyperactive/impulsive behaviors in a community sample of children

OBJECTIVE

This study examined relationships between inattentive and hyperactive/impulsive behaviors and working memory (WM) functioning, and the utility of WM in categorical diagnosis of ADHD versus considering ADHD symptoms on a continuum.

METHOD

The study included 50 male children (6-12 years). Inattentive and hyperactive/impulsive behaviors were measured by the Conners-3P parent report, and WM was assessed by the WISC-IV WM subtests and Working Memory Index (WMI).

RESULTS

WISC-IV Arithmetic and Digit Span Backward were most consistently related to inattentive behaviors, and no WM measure was consistently related to ADHD hyperactive/impulsive behaviors. Arithmetic and Digit Span Backward also accounted for significant variance in inattentive behaviors and ADHD inattention symptoms, respectively. Neither the WMI nor the Arithmetic subtest correctly classified individuals diagnosed with ADHD.

CONCLUSION

Measurement of inattentive behaviors on a continuum best characterized relationships between symptoms of ADHD and WM functioning; WM functioning did not have utility in categorical understanding of ADHD.

Evaluating the Hierarchical Structure of ADHD Symptoms and Invariance Across Age and Gender

The bifactor model of attention-deficit/hyperactivity disorder (ADHD) has been extensively explored, yet the tendency of the bifactor model to overfit data necessitates investigation of alternative, more parsimonious models, such as a modified bifactor structure. The present study used item response theory to compare unidimensional, correlated factors, bifactor, and modified bifactor models of ADHD symptoms in a clinical sample of youth ( N = 1,612) and examined differential item functioning (DIF) by age (<11 and ≥11 years) and gender. Results suggested that two restricted bifactor models showed superior fit compared with alternative models, and support strong general and inattention dimensions, with unreliable hyperactivity and impulsivity dimensions. No DIF was found across gender or age. The present study confirms that the general dimension (i.e., inhibition) and one specific dimension (i.e., sustained attention) represent distinct variability in ADHD symptoms that may improve prediction of symptom persistence, treatment response, or functional outcomes.

Future Directions for Work on Refinement of ADHD Assessment in Young Adults

Sibley, Coxe, and Molina provide a thoughtful discussion of the implications of our study and highlight important future directions in this line of work. They helpfully amplify several themes that space did not allow discussion of in our article. In particular, they correctly emphasize the importance of theoretical as well as statistical considerations in model selection. We also agree that clinical tests of sensitivity and specificity, taking into account different base rates and types of samples, are essential before a final algorithm would be ready for dissemination. However, we are not convinced that such tests should be limited to populations of individuals with attention-deficit/hyperactivity disorder (ADHD). Rather, they should include those with and without diagnosed ADHD in order to provide comprehensive tests of reporter sensitivity and specificity across the entire continuum of ADHD symptomatology and in relation to different populations, including other disorders and typically developing populations.

ADHS bei Erwachsenen

Zusammenfassung. Klassifizierungs- und Strukturierungsmöglichkeiten psychischer Störungen und Konstrukte sind in den letzten Jahren zu einem Schwerpunkt empirischer Forschung geworden. Im Mittelpunkt steht dabei die Debatte um die bisherige kategoriale versus einer neuen dimensionalen Sichtweise. ADHS gehört zu den Störungsbildern, für welche ein dimensionales Konzept plausibel erscheint. Empirische Belege hierfür liefern verschiedene taxonomische Studien an Kindern und Jugendlichen mit ADHS. Für Erwachsene gibt es bisher nur wenig empirische Untersuchungen zu dem Thema. Daher ist die vorliegende Studie eine erste Auseinandersetzung mit der Beschaffenheit von ADHS bei Erwachsenen, wobei den Befunden bei Kindern folgend von einer dimensionalen Struktur ausgegangen wird. Zwei Stichproben wurden zur Beantwortung der Fragestellung herangezogen: 605 Personen einer gesunden Normalstichprobe und 722 Personen aus einer klinischen Stichprobe, bestehend aus 336 Personen ohne ADHS-Diagnose und 386 Personen mit ADHS-Diagnose. Untersucht wurden alle Personen mittels der ADHS-Selbstbeurteilungsskala (ADHS-SB). Zur statistischen Überprüfung der Fragestellung wurden Diskriminanzanalysen und eine Faktorenanalyse durchgeführt, weiterhin wurden finite Mischverteilungsmodelle mit Hilfe des EM-Algorithmus gerechnet. Die Diskriminanzanalysen konnten zeigen, dass Grenzwerte nur bedingt dazu in der Lage sind, zwischen Personen mit und ohne ADHS zu diskriminieren. Die Faktorenanalyse ergab für alle Gruppen die gleiche Zwei-Faktoren-Lösung der ADHS, welche auch vom DSM-5 vorgeschlagen wird (Unaufmerksamkeit, Hyperaktivität/Impulsivität). Weiterhin wiesen die Mischmodelle der verschiedenen Gruppen keine Unterschiede auf, welche eine kategoriale Sichtweise rechtfertigen würden. Insgesamt ist eine dimensionale Struktur des Störungsbildes auch bei Erwachsenen als wahrscheinlich anzunehmen. Dies bedeutet, dass die Symptome der ADHS extreme Ausprägungen normaler psychischer Phänomene darstellen und es keine klaren Grenzen zwischen Personen mit und ohne einer adulten ADHS gibt. Trotz möglicher dimensionaler Struktur handelt es sich bei der ADHS um eine psychische Störung. Das Abklären funktioneller Beeinträchtigungen könnte vermehrt helfen, Behandlungswürdigkeit festzustellen.

Bifactor Models of Attention Deficit/Hyperactivity Symptomatology in Adolescents: Criterion Validity and Implications for Clinical Practice

This study evaluated the fit and criterion validity of a bifactor model for 18 DSM-IV attention deficit/hyperactivity disorder (ADHD) symptoms, along with nine supplementary symptoms that represented the manifestation of inattention and hyperactivity-impulsivity in adolescence and early adulthood. Participants included N = 172 adolescents who were diagnosed with combined type ADHD and who were enrolled in a treatment study. A bifactor model provided reasonably good fit to combined parent- and teacher-reported DSM symptoms and supplemental items at baseline prior to treatment. Across models, the general factor was characterized by high reliability (ω = .93, .95), while specific inattentive and hyperactive-impulsive factors were characterized by poor reliability (ω = .30-.50). With respect to criterion validity, the general ADHD and specific inattentive factors were uniquely associated with home and school impairment (R² = .13-.29) but not adolescent risk-tasking behavior. Results are discussed with respect to the ways in which bifactor models of ADHD inform the diagnostic criteria for ADHD.

Does the Environment Have an Enduring Effect on ADHD? A Longitudinal Study of Monozygotic Twin Differences in Children

Environmental factors play a key role in the development of Attention-Deficit/Hyperactivity Disorder (ADHD), but the long-term effects of these factors are still unclear. This study analyses data from 1024 monozygotic (identical) twins in Australia, the United States, and Scandinavia who were assessed for ADHD in Preschool, Kindergarten, Grade 1, and Grade 2. Differences within each twin pair were used as a direct measure of non-shared environmental effects. The Trait-State-Occasion (TSO) model developed by Cole et al. (Psychological Methods, 10, 3-20, 2005) was used to separate the non-shared environmental effects into stable factors, and transient factors that excluded measurement error. Stable factors explained, on average, 44 % and 39 % of the environmental variance in hyperactive-impulsive and inattentive symptoms, respectively. Transient effects explained the remaining 56 % and 60 % of variance. The proportion of stable variance was higher than expected based on previous research, suggesting promise for targeted interventions if future research identifies these stable risk factors.

Preschool Neuropsychological Measures as Predictors of Later Attention Deficit Hyperactivity Disorder

The present study examined preschool neuropsychological measures as predictors of school-age attention deficit hyperactivity disorder (ADHD). Participants included 168 children (91 males) who completed neuropsychological measures at ages 3 and 4, and who were evaluated for ADHD and oppositional defiant disorder at age 6. The Conners' Kiddie Continuous Performance Test (K-CPT), NEPSY Statue subtest, and a delay aversion task significantly distinguished at-risk children who later did and did not meet criteria for ADHD, with poor to fair overall predictive power, specificity, and sensitivity. However, only the K-CPT ADHD Confidence Index and battery added incremental predictive validity beyond early ADHD symptoms. This battery approach, which required impairment on at least 2 of the 3 significant measures, yielded fair overall predictive power, specificity, and sensitivity, and correctly classified 67 % of children. In addition, there was some support for the specificity hypothesis, with evidence that cool executive function measures (K-CPT and Statue subtest) tended to predict inattentive symptoms. These findings suggest that neuropsychological deficits are evident by preschool-age in children with ADHD, but neuropsychological tests may still misclassify approximately one-third of children if used alone. Thus, neuropsychological measures may be a useful component of early ADHD assessments, but should be used with caution and in combination with other assessment methods.

A hierarchical causal taxonomy of psychopathology across the life span

We propose a taxonomy of psychopathology based on patterns of shared causal influences identified in a review of multivariate behavior genetic studies that distinguish genetic and environmental influences that are either common to multiple dimensions of psychopathology or unique to each dimension. At the phenotypic level, first-order dimensions are defined by correlations among symptoms; correlations among first-order dimensions similarly define higher-order domains (e.g., internalizing or externalizing psychopathology). We hypothesize that the robust phenotypic correlations among first-order dimensions reflect a hierarchy of increasingly specific etiologic influences. Some nonspecific etiologic factors increase risk for all first-order dimensions of psychopathology to varying degrees through a general factor of psychopathology. Other nonspecific etiologic factors increase risk only for all first-order dimensions within a more specific higher-order domain. Furthermore, each first-order dimension has its own unique causal influences. Genetic and environmental influences common to family members tend to be nonspecific, whereas environmental influences unique to each individual are more dimension-specific. We posit that these causal influences on psychopathology are moderated by sex and developmental processes. This causal taxonomy also provides a novel framework for understanding the heterogeneity of each first-order dimension: Different persons exhibiting similar symptoms may be influenced by different combinations of etiologic influences from each of the 3 levels of the etiologic hierarchy. Furthermore, we relate the proposed causal taxonomy to transdimensional psychobiological processes, which also impact the heterogeneity of each psychopathology dimension. This causal taxonomy implies the need for changes in strategies for studying the etiology, psychobiology, prevention, and treatment of psychopathology. (PsycINFO Database Record

Are There Executive Dysfunction Subtypes Within ADHD?

OBJECTIVE

Children with ADHD have heterogeneous behavioral and neuropsychological profiles. The aim of this study was to examine the possible utility of executive function (EF) subtypes within ADHD.

METHOD

Participants were 357 children aged 6 through 13 with a diagnosis of ADHD. Children completed a brief laboratory battery measuring EF, including response inhibition, response variability, speed, and set-shifting. Children also completed standardized intelligence and achievement testing.

RESULTS

Two-way cluster analysis of EF profiles of children with ADHD produced a three-cluster solution, labeled poor inhibitory control, poor set-shifting/speed, and intact task performance. Clusters significantly differed in measures of intelligence, academic achievement, and other disruptive behavior and anxiety/mood symptoms.

CONCLUSION

These findings further support the idea that children with ADHD have heterogeneous EF profiles and suggest that the theory of ADHD should consider these individual differences in EF profiles within the ADHD diagnostic category.

Comorbid Development of Disruptive Behaviors from age 1½ to 5 Years in a Population Birth-Cohort and Association with School Adjustment in First Grade

Comorbidity is frequent among disruptive behaviors (DB) and leads to mental health problems during adolescence and adulthood. However, the early developmental origins of this comorbidity have so far received little attention. This study investigated the developmental comorbidity of three DB categories during early childhood: hyperactivity-impulsivity, non-compliance, and physical aggression. Joint developmental trajectories of DB were identified based on annual mother interviews from age 1½ to 5 years, in a population-representative birth-cohort (N = 2045). A significant proportion of children (13 % to 21 %, depending on the type of DB) consistently displayed high levels of hyperactivity-impulsivity, non-compliance, or physical aggression from age 1½ to 5 years. Developmental comorbidity was frequent, especially for boys: 10 % of boys and 3.7 % of girls were on a stable trajectory with high levels of symptoms for the three categories of DB. Significant associations were observed between preschool joint-trajectories of DB and indicators of DB and school adjustment assessed by teachers in first grade. Preschoolers who maintained high levels of hyperactivity-impulsivity, non-compliance, and physical aggression, displayed the highest number of DB symptoms in first grade for all categories according to their teacher. They were also among the most disadvantaged of their class for school adjustment indicators. Thus, DB manifestations and developmental comorbidity of DB are highly prevalent in infancy. Early childhood appears to be a critical period to prevent persistent and comorbid DB that leads to impairment at the very beginning of school attendance and to long-term serious health and social adjustment problems.

Predictors of adolescent outcomes among 4-6-year-old children with attention-deficit/hyperactivity disorder

Children who met Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) criteria for attention-deficit/hyperactivity disorder (ADHD) with functional impairment in at least one setting at 4-6 years of age were followed prospectively through age 18 years. On average, the 125 children (107 boys) with ADHD at baseline improved over time, but still continued to exhibit more symptoms, functional impairment, and risky behavior through adolescence than demographically matched healthy comparison children. These findings support the predictive validity of the diagnosis of ADHD at younger ages by demonstrating that the symptoms and impairment are enduring. Nonetheless, there were marked variations in developmental outcomes. Among children with ADHD, higher numbers of inattention and hyperactivity-impulsivity symptoms and higher number of concurrent symptoms (oppositional, conduct disorder, anxiety, and depression) measured at baseline each predicted higher future levels of the same dimension of symptoms. In addition, higher baseline levels of inattention, oppositional, conduct disorder, and anxiety symptoms predicted greater future functional impairment. Among children with ADHD, girls and children from families with lower family incomes had relatively poorer outcomes. Although outcomes varied along a continuum, approximately 10% of the children with ADHD at 4-6 years could be classified as functioning in the normative range on multiple measures during 15-18 years. Although this finding awaits replication, lower levels of hyperactivity-impulsivity symptoms at 4-6 years predicted more normative functioning during adolescence. These findings suggest that ADHD identified in early childhood predicts an increased likelihood of functional impairment through adolescence for most, but not all, children.

Aiding the diagnosis of AD/HD in childhood: Using actigraphy and a continuous performance test to objectively quantify symptoms

The current gold standard for the diagnosis of AD/HD is based on subjective reports from teachers, parents, and clinicians. These measures can be problematic as they are open to rater biases and also fail to account for the developmental nature of symptoms. The current study examined the diagnostic accuracy of two objective measures, a computer-based Continuous Performance Task and actigraphy (e.g. motion tracking device) in differentiating children with AD/HD (N=70) from healthy controls (N=70). It was predicted that task-unrelated movement (measured via actigraphy) during a CPT and CPT performance would have high classification accuracy in differentiating children with AD/HD from healthy controls, and that the inclusion of age would increase this accuracy. Results indicated that total energy expenditure from the task-unrelated wrist and ankle movement during the CPT was higher in children with AD/HD than controls, and that CPT performance was poorer in AD/HD than controls. Discriminant function analyses revealed that the CPT Full-Scale Response Control Quotient and wrist and ankle energy expenditure provided optimal classification accuracy - correctly classifying 86% of cases, with sensitivity of 81.4% and specificity of 91.4%. The prediction that classification accuracy would increase with the inclusion of age was not supported by the data. When taken in conjunction with other clinical assessments, these findings suggest that actigraphy during a CPT and CPT performance may increase the probability of a correct AD/HD diagnosis.

Preschool ADHD Diagnosis and Stimulant Use Before and After the 2011 AAP Practice Guideline

OBJECTIVE

To evaluate the change in the diagnosis of attention-deficit/hyperactivity disorder (ADHD) and prescribing of stimulants to children 4 to 5 years old after release of the 2011 American Academy of Pediatrics guideline.

METHODS

Electronic health record data were extracted from 63 primary care practices. We included preventive visits from children 48 to 72 months old receiving care from January 2008 to July 2014. We compared rates of ADHD diagnosis and stimulant prescribing before and after guideline release using logistic regression with a spline and clustering by practice. Patterns of change (increase, decrease, no change) were described for each practice.

RESULTS

Among 87 067 children with 118 957 visits before the guideline and 56 814 with 92 601 visits after the guideline, children had an ADHD diagnosis at 0.7% (95% confidence interval [CI], 0.7% to 0.8%) of visits before and 0.9% (95% CI, 0.8% to 0.9%) after guideline release and had stimulant prescriptions at 0.4% (95% CI, 0.4% to 0.4%) of visits in both periods. A significantly increasing preguideline trend in ADHD diagnosis ended after guideline release. The rate of stimulant medication use remained constant before and after guideline release. Patterns of change from before to after the guideline varied significantly across practices.

CONCLUSIONS

Release of the 2011 guideline that addressed ADHD in preschoolers was associated with the end of an increasing rate of diagnosis, and the rate of prescribing stimulants remained constant. These are reassuring results given that a standardized approach to diagnosis was recommended and stimulant treatment is not first-line therapy for this age group.

Effect of Ferritin on Short-Term Treatment Response in Attention Deficit Hyperactivity Disorder

OBJECTIVES

Several studies have shown that iron deficiency and ferritin levels are associated with parent and teacher Attention Deficit Hyperactivity Disorder (ADHD) ratings. Although there are conflicting results, it has also been reported that iron supplementation may help to decrease ADHD symptoms. When all these previous studies are taken into account, it is clear that a large study investigating the effects of iron deficiency and ferritin levels on routine pharmacological treatment of ADHD with stimulants would be helpful to elucidate this treatment from a clinical point of view.

METHODS

A total of 345 subjects with combined or predominantly hyperactive-impulsive (PHI) subtypes of ADHD were included. All diagnoses were based on the DSM-IV criteria and ascertained by direct interviews conducted by the authors, who are experienced child psychiatrists certified in the use of the Schedule for Affective Disorders and Schizophrenia for School-Age Children - Present and Lifetime Version (K-SADS-PL) semi-structured interview. The two treatment response criteria were: 1) 25% or more decrease in pre-treatment Conners Parent Rating Scale (CPRS) and Conners Teacher Rating Scale (CTRS) Hyperactivity (HA) and Total Problems scores; 2) CPRS and CTRS HA scores lower than the cut-off point ("very improved").

RESULTS

A total of 255 (73.9%) patients were on OROS-methylphenidate (OROS-MPH) and 90 (26.1%) were on immediate release methylphenidate (IR-MPH). The mean±sd of OROS-MPH and IR-MPH doses were 28.8±8.1 and 20.9±7.1 mg, respectively. More than half (52.5%) of the subjects were previously drug-naive at treatment inception. Two hundred and seventy eight (80.6%) subjects had combined subtype ADHD and the remainder had predominantly hyperactive-impulsive subtype. Only 60 (17.4%) of the subjects had no comorbid disorders, while 38.3% had one comorbid disorder, 32.8% had two comorbid disorders, and 11.6% had three or more comorbid disorders. The most frequent comorbidity was Oppositional Defiant Disorder/Conduct Disorder (ODD/CD, 51.6%), followed by Learning Disabilities (LD, 35.4%) and Anxiety Disorders (AD, 15.9%). Logistic regression analysis showed that subjects with comorbid ODD/CD and LD were less likely to respond to treatment. Ferritin levels and iron deficiency were not associated significantly with outcomes.

CONCLUSIONS

In a large sample of subjects with combined or predominantly hyperactive-impulsive subtypes of ADHD, after controlling for several factors, we found that neither iron deficiency (ferritin <12 ng/ml) nor ferritin levels were associated with less favorable short-term treatment outcomes with stimulants. Subjects with comorbid ODD/CD and LD were less likely to have a 25% or more decrease in CTRS Total score. The presence of ODD/CD was also a negative predictor of treatment response in terms of CPRS Total and HA scores. The lack of a negative treatment response in ADHD subjects with iron deficiency and lack of a negative association with ferritin levels suggest that the relationship between iron metabolism and ADHD, a highly heterogeneous disorder, may be more complicated than previously believed.

Parent-reported symptoms, impairment, helpfulness of treatment, and unmet service needs in a follow-up of outpatient children with attention-deficit/hyperactivity disorder

BACKGROUND

Limited information exists regarding the associations between impairment, symptoms, helpfulness of treatments, and service needs after initial treatment of children with attention-deficit/hyperactivity disorder (ADHD).

AIMS

The aims of this study were to examine persistence rates and associations between parent-reported symptoms, impairment, helpfulness of treatments, and service needs in a retrospective follow-up study of children with ADHD.

METHODS

Parents of 214 children with a mean age of 12.6 years (SD = 2.1) who were diagnosed with ADHD at five child and adolescent mental health clinics (CAMHS) completed questionnaires 1-10 years (mean = 3.7 years, SD = 2.2) after baseline assessment. The response rate was 43.4%. A community comparison group (n = 110) was recruited from the same area.

RESULTS

Approximately two-thirds (60.3%) of the sample fulfilled the DSM-IV symptom criteria of ADHD at follow-up, 84.3% were functionally impaired, and most children (84.7%) were on medication. Inattentive and emotional symptoms were the strongest predictors of impairment across impairment areas. Perceived helpfulness of different treatments varied from 71.8-88.7%, and no significant difference was found between the ADHD sub-groups regarding reported helpfulness. 'Adjustment of the school situation' was the most frequent service need, and approximately half of the parents reported needs for care co-ordination. Children fulfilling the symptom criteria of the ADHD Combined sub-group were most impaired and had most service needs.

CONCLUSIONS

At follow-up, children were highly symptomatic and impaired, despite a high rate of persistent medication treatment. The findings underline the need for more tailored treatment and co-ordinated care over time.

Understanding Heterogeneity in Clinical Cohorts Using Normative Models: Beyond Case-Control Studies

BACKGROUND

Despite many successes, the case-control approach is problematic in biomedical science. It introduces an artificial symmetry whereby all clinical groups (e.g., patients and control subjects) are assumed to be well defined, when biologically they are often highly heterogeneous. By definition, it also precludes inference over the validity of the diagnostic labels. In response, the National Institute of Mental Health Research Domain Criteria proposes to map relationships between symptom dimensions and broad behavioral and biological domains, cutting across diagnostic categories. However, to date, Research Domain Criteria have prompted few methods to meaningfully stratify clinical cohorts.

METHODS

We introduce normative modeling for parsing heterogeneity in clinical cohorts, while allowing predictions at an individual subject level. This approach aims to map variation within the cohort and is distinct from, and complementary to, existing approaches that address heterogeneity by employing clustering techniques to fractionate cohorts. To demonstrate this approach, we mapped the relationship between trait impulsivity and reward-related brain activity in a large healthy cohort (N = 491).

RESULTS

We identify participants who are outliers within this distribution and show that the degree of deviation (outlier magnitude) relates to specific attention-deficit/hyperactivity disorder symptoms (hyperactivity, but not inattention) on the basis of individualized patterns of abnormality.

CONCLUSIONS

Normative modeling provides a natural framework to study disorders at the individual participant level without dichotomizing the cohort. Instead, disease can be considered as an extreme of the normal range or as-possibly idiosyncratic-deviation from normal functioning. It also enables inferences over the degree to which behavioral variables, including diagnostic labels, map onto biology.

Informant Discrepancies in the Assessment of Attention-Deficit/Hyperactivity Disorder

An attention-deficit/hyperactivity disorder (ADHD) diagnosis requires symptoms to be present across two or more settings, thus requiring information from multiple informants. Research consistently shows low to moderate agreement between parents and teachers; however, the mechanisms underlying these discrepancies remain unclear. This study examined (a) agreement between parents and teachers, (b) effects of using different combination rules in assigning diagnoses, and (c) the role of contextual influences and/or personal biases in informants’ reports. Fifty-five children, their parents, and teachers participated. Parent and teacher ratings on the Attention-Deficit/Hyperactivity Disorder Rating Scale–Fourth edition (ADHD-RS-IV) and clinician ratings on the Behavioral Observation of Students in Schools (BOSS) were obtained. Results indicated moderate agreement among parent and teacher ratings on the ADHD-RS. Diagnostically, the rule for combining information from multiple informants dramatically altered the ADHD classification assigned to the child. With regard to rater differences, the clinician-rated school observation gave some support for the notion that ratings are person rather than context specific.

Integrating care for neurodevelopmental disorders by unpacking control: A grounded theory study

BACKGROUND

To establish integrated healthcare pathways for patients with neurodevelopmental disorders (ND) such as autism spectrum disorder and attention-deficit hyperactivity disorder is challenging. This study sets out to investigate the main concerns for healthcare professionals when integrating ND care pathways and how they resolve these concerns.

METHODS

Using classic grounded theory (Glaser), we analysed efforts to improve and integrate an ND care pathway for children and youth in a Swedish region over a period of 6 years. Data from 42 individual interviews with a range of ND professionals, nine group interviews with healthcare teams, participant observation, a 2-day dialogue conference, focus group meetings, regional media coverage, and reports from other Swedish regional ND projects were analysed.

RESULTS

The main concern for participants was to deal with overwhelming ND complexity by unpacking control, which is control over strategies to define patients' status and needs. Unpacking control is key to the professionals' strivings to expand constructive life space for patients, to squeeze health care to reach available care goals, to promote professional ideologies, and to uphold workplace integrity. Control-seeking behaviour in relation to ND unpacking is ubiquitous and complicates integration of ND care pathways.

CONCLUSIONS

The Unpacking control theory expands central aspects of professions theory and may help to improve ND care development.

CATEGORICAL DIAGNOSIS OF EXTREME HYPERACTIVITY, IMPULSIVITY, AND INATTENTION IN VERY YOUNG CHILDREN

Severe hyperactivity and impulsivity are common reasons for referral to infant mental health services. Past versions of ZERO TO THREE's () diagnostic nosology, the Diagnostic Classification of Mental and Developmental Disorders in Infancy and Early Childhood (DC:0-3), did not address this clinical issue because it had been addressed in other nosologies. These general diagnostic nosologies describe attention deficit hyperactivity disorder (ADHD), but with little attention to developmentally specific aspects of the diagnosis in very young children. Categorical diagnosis related to hyperactivity and impulsivity in very young children warrants careful review of existing literature. Explicit attention must be paid to ensure that categorical diagnoses serve to describe syndromes that cause significant impairment to the family to allow children and families to access effective supports and ensure that behaviors typical of the developmental level are not described as pathologic. This article reviews proposed diagnostic criteria for ADHD and overactivity disorder of toddlerhood as well as the rationale for the criteria and evidence supporting validity and reliability of the diagnoses in very young children. Clinical implications also are presented.

Beyond Lumping and Splitting: A Review of Computational Approaches for Stratifying Psychiatric Disorders

Heterogeneity is a key feature of all psychiatric disorders that manifests on many levels, including symptoms, disease course, and biological underpinnings. These form a substantial barrier to understanding disease mechanisms and developing effective, personalized treatments. In response, many studies have aimed to stratify psychiatric disorders, aiming to find more consistent subgroups on the basis of many types of data. Such approaches have received renewed interest after recent research initiatives, such as the National Institute of Mental Health Research Domain Criteria and the European Roadmap for Mental Health Research, both of which emphasize finding stratifications that are based on biological systems and that cut across current classifications. We first introduce the basic concepts for stratifying psychiatric disorders and then provide a methodologically oriented and critical review of the existing literature. This shows that the predominant clustering approach that aims to subdivide clinical populations into more coherent subgroups has made a useful contribution but is heavily dependent on the type of data used; it has produced many different ways to subgroup the disorders we review, but for most disorders it has not converged on a consistent set of subgroups. We highlight problems with current approaches that are not widely recognized and discuss the importance of validation to ensure that the derived subgroups index clinically relevant variation. Finally, we review emerging techniques-such as those that estimate normative models for mappings between biology and behavior-that provide new ways to parse the heterogeneity underlying psychiatric disorders and evaluate all methods to meeting the objectives of such as the National Institute of Mental Health Research Domain Criteria and Roadmap for Mental Health Research.

ADHD subtypes and neuropsychological performance in an adult sample

The study investigated, with an adult sample, the hypothesis that differences between subtypes of ADHD on neuropsychological tests contribute to the poor separation of ADHD and healthy groups on tests of this kind. Groups of ADHD inattentive (n=16) and combined (n=16) subtypes were carefully identified using DSM-IV criteria, and their performance on 14 measures of attention, memory, and executive function (EF) was compared between subtypes and between the two subtypes combined and a group of healthy controls (n=30). Multivariate analyses showed statistically significant differences between the two subtypes, and between the two subtypes combined and the healthy controls. Importantly for the hypothesis, where differences for neuropsychological tests in terms of effect sizes between subtypes were largest, the differences in effect sizes between the two groups combined and controls were smallest (r=-0.64, 95% CI [-0.15, -0.87]).

The Relation Between Inattentive and Hyperactive/Impulsive Behaviors and Early Mathematics Skills

OBJECTIVE

Despite strong evidence that inattentive and hyperactive/impulsive behaviors are associated with mathematical difficulties in school-age children, little research has been conducted to examine the link between these constructs before the start of formal education. The purpose of this study was to examine how different manifestations of inattentive and hyperactive/impulsive behaviors, as measured by different assessment tools, are related to early mathematics skills in preschoolers.

METHOD

Eighty-two preschool children completed a measure of early mathematics and the Continuous Performance Test (CPT). Teachers rated children's behaviors using the Conners' Teacher Rating Scale-15 Item. Sixty-five of these children completed mathematics assessments 1 year later.

RESULTS

Teacher ratings of inattention were uniquely related to concurrent early mathematics skills, whereas CPT errors were uniquely predictive of early mathematics skills 1 year later.

CONCLUSION

Findings have implications for the understanding and assessment of behavior problems that are associated with early mathematics difficulties.

Co-Occurrence of ADHD and Anxiety in Preschool Children

OBJECTIVE

The objective of this study was to examine co-occurrence of ADHD and anxiety in preschool children.

METHOD

The data collection was part of the Norwegian Mother and Child Cohort Study (MoBa) at the Norwegian Institute of Public Health. After a screening for ADHD symptoms at 36 months, participants were clinically assessed at age 36 to 44 months. Psychiatric symptoms of ADHD and anxiety were derived from the Preschool Age Psychiatric Assessment (PAPA) interview.

RESULTS

In preschoolers with ADHD symptoms, 33% were reported to have symptoms of anxiety. Children with symptoms of ADHD and anxiety had more severe ADHD symptomatology, and particularly more inattentive symptoms compared with children with ADHD symptoms and no anxiety.

CONCLUSION

Clinicians should be aware of the frequent overlap between symptoms of anxiety and ADHD in preschoolers as different intervention strategies may be required.

Neuropsychological performance measures as intermediate phenotypes for attention-deficit/hyperactivity disorder: A multiple mediation analysis

Genetic influences on dopaminergic neurotransmission have been implicated in attention-deficit hyperactivity disorder (ADHD) and are theorized to impact cognitive functioning via alterations in frontal-striatal circuitry. Neuropsychological functioning has been proposed to account for the potential associations between dopamine candidate genes and ADHD. However, to date, this mediation hypothesis has not been directly tested. Participants were 498 youth ages 6-17 years (mean M = 10.8 years, SD = 2.4 years, 55.0% male). All youth completed a multistage, multiple-informant assessment procedure to identify ADHD and non-ADHD cases, as well as a comprehensive neuropsychological battery. Youth provided a saliva sample for DNA analyses; the 480 base pair variable number of tandem repeat polymorphism of the dopamine active transporter 1 gene (DAT1) and the 120 base pair promoter polymorphism of the dopamine receptor D4 gene (DRD4) were genotyped. Multiple mediation analysis revealed significant indirect associations between DAT1 genotype and inattention, hyperactivity-impulsivity, and oppositionality, with specific indirect effects through response inhibition. The results highlight the role of neurocognitive task performance, particularly response inhibition, as a potential intermediate phenotype for ADHD, further elucidating the relationship between genetic polymorphisms and externalizing psychopathology.

Altered response-preparation in patients with adult ADHD: A high-density ERP study

Aberrations in early-developing bottom-up processes, such as stimulus-driven response preparation, are thought to play a critical role in the onset of ADHD, and in its persistence over time. Electrophysiology offers a unique tool to gain insight into response preparation, since response preparation has been associated with distinctive ERP changes, including negative potential-shifts which occur predominantly over frontal brain areas. We examined response-preceding negative potential shifts (RPNS) as a probe of response-preparation in adult ADHD patients by obtaining high-density event-related potentials from 33 ADHD and 29 matched healthy subjects during a Go/Nogo task using a 128-channel BioSemi recording-system. Compared to controls, ADHD patients showed enhancement of the RPNS in fronto-central brain regions in the Go condition during correct responses. This change was associated with poor performance in the Stroop incongruency-task: the greater the enhancement, the higher the proportion of errors. Moreover, the ERP-enhancement showed association with the severity of ADHD-symptoms; and with heightened response-variability. Thus, ADHD patients demonstrate neurophysiological alterations in response-preparation and response-preceding brain activity, suggestive of excessive activation of prefrontal neural circuits. Given the correlation with neuropsychological and psychopathological measures, these changes may constitute a pathway for core symptoms of ADHD, including premature and impaired response-preparation and motor-hyperactivity.

Neuropsychological heterogeneity in preschool ADHD: investigating the interplay between cognitive, affective and motivation-based forms of regulation

There is a trend toward diagnosing ADHD prior to school entry. Despite this, there is a lack of studies investigating ADHD in the preschool years, at least studies including a large range of different neuropsychological functions. Our knowledge of the independent effects of different neuropsychological functions in relation to preschool ADHD is therefore limited. In order to address this issue, the present study investigated cognitive, affective, and motivation-based regulation in relation to ADHD symptoms in 104 preschool children (age M = 67.33 months, SD = 10.10; 65 % boys). Results showed that these regulatory processes were all significantly related to ADHD symptoms and that most of these relations remained after controlling for comorbid conduct problems. Most previous preschool studies have only included cognitive regulation, and to some extent motivation-based regulation. By also including affective regulation, we were able to explain a larger proportion of the variance in ADHD symptoms. However, it should be noted that the amount of variance explained was still small in comparison with what has been found in previous studies of school-aged children. This finding could be taken as an indication that further studies examining the nature of preschool ADHD are needed, and that it may be necessary to look beyond the neuropsychological factors that have been linked to the disorder in older children and adults.

The Effectiveness and Tolerability of Central Nervous System Stimulants in School-Age Children with Attention-Deficit/Hyperactivity Disorder and Disruptive Mood Dysregulation Disorder Across Home and School

OBJECTIVE

This study examines the effectiveness and tolerability of stimulants in children with attention-deficit/hyperactivity disorder (ADHD) and disruptive mood dysregulation disorder (DMDD).

METHODS

To be eligible, participants had to meet Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM-IV) criteria for the combined subtype of ADHD and National Institute of Mental Health (NIMH) severe mood dysregulation criteria. The Diagnostic and Statistical Manual of Mental Disorders, 5th ed. (DSM-V) DMDD criteria were retrospectively assessed after the study was completed. An open-label medication trial lasting up to 6 weeks was completed to optimize the central nervous system (CNS) stimulant dose. Measures of affective symptoms, ADHD symptoms and other disruptive behaviors, impairment, and structured side effect ratings were collected before and after the medication trial.

RESULTS

Optimization of stimulant medication was associated with a significant decline in depressive symptoms on the Childhood Depression Rating Score-Revised Scale (p<0.05, Cohen's d=0.61) and Mood Severity Index score (p<0.05, Cohen's d=0.55), but not in manic-like symptoms on the Young Mania Rating Scale. There was a significant reduction in ADHD (p<0.05, Cohen's d=0.95), oppositional defiant disorder (ODD) (p<0.05, Cohen's d=0.5), and conduct disorder (CD) symptoms (p<0.05, Cohen's d=0.65) as rated by parents. There was also a significant reduction in teacher-rated ADHD (p<0.05, Cohen's d=0.33) but not in ODD symptoms. Medications were well tolerated and there was no increase in side effect ratings seen with dose optimization. Significant improvement in functioning was reported by clinicians and parents (all p's<0.05), but youth still manifested appreciable impairment at end-point.

CONCLUSIONS

CNS simulants were well tolerated by children with ADHD comorbid with a diagnosis of DMDD. CNS stimulants were associated with clinically significant reductions in externalizing symptoms, along with smaller improvements in mood. However, most participants still exhibited significant impairment, suggesting that additional treatments may be needed to optimize functioning.

Trait and State Variance in Multi-Informant Assessments of ADHD and Academic Impairment in Spanish First-Grade Children

OBJECTIVE

We examined the stable trait and variable state components of ADHD-inattention (IN), ADHD-hyperactivity/impulsivity (HI), and academic impairment (AI) dimensions using mothers', fathers', primary and secondary teachers' ratings of children's behavior at home and school. We also examined between-informant agreement with regard to trait and state components.

METHOD

Mothers, fathers, primary and secondary teachers rated HI, IN, and AI in N = 758 Spanish first grade children (55% boys) over three measurement occasions across 12 months.

RESULTS

Latent state-trait analyses revealed that mothers', fathers', and primary teachers' (but not secondary teachers') ratings reflected more trait variance for ADHD-HI (M = 73%), ADHD-IN (M = 74%), and AI (M = 76%) than occasion-specific variance (M = 27%, M = 26%, and M = 24%, respectively). Fathers' ratings shared a meaningful level of trait variance with mothers' ratings of ADHD-HI and ADHD-IN (range 78% to 82%), whereas primary and secondary teachers' ratings shared lower levels of trait variance with mothers' ratings (range 41% to 63%). The trait components of fathers', primary teachers', and secondary teachers' ratings of AI showed high levels of convergence with mothers' ratings (88%, 70%, and 59% respectively).

CONCLUSIONS

ADHD symptom reports reflect both trait (48 to 86%) and state (14 to 53%) variance components. The lower amount of shared variability between home and school suggests the setting-specificity of trait and state components of ADHD symptoms. Our findings indicate that ADHD symptom reports may reflect context-specific traits, suggesting the importance of differentiating and targeting ADHD behaviors across different settings.

Developmental trajectories of clinically significant attention-deficit/hyperactivity disorder (ADHD) symptoms from grade 3 through 12 in a high-risk sample: Predictors and outcomes

Developmental trajectories of clinically significant attention-deficit/hyperactivity (ADHD) symptoms were explored in a sample of 413 children identified as high risk because of elevated kindergarten conduct problems. Symptoms of inattention and hyperactivity-impulsivity were modeled simultaneously in a longitudinal latent class analyses, using parent reports collected in Grades 3, 6, 9, and 12. Three developmental trajectories emerged: (1) low levels of inattention and hyperactivity (low), (2) initially high but then declining symptoms (declining), and (3) continuously high symptoms that featured hyperactivity in childhood and early adolescence and inattention in adolescence (high). Multinomial logistic regressions examined child characteristics and family risk factors as predictors of ADHD trajectories. Relative to the low class, children in the high and declining classes displayed similar elevations of inattention and hyperactivity in early childhood. The high class was distinguished from the declining class by higher rates of aggression and hyperactivity at school and emotion dysregulation at home. In contrast, the declining class displayed more social isolation at home and school, relative to the low class. Families of children in both high and declining trajectory classes experienced elevated life stressors, and parents of children in the high class were also more inconsistent in their discipline practices relative to the low class. By late adolescence, children in the high class were significantly more antisocial than those in the low class, with higher rates of arrests, school dropout, and unemployment, whereas children in the declining class did not differ from those in the low trajectory class. The developmental and clinical implications of these findings are discussed.

Empirically Determined, Psychopathological Subtypes in Children With ADHD

OBJECTIVE

The aim of this study was to empirically determine subgroups of ADHD defined by specific patterns of psychopathology.

METHOD

A clinical sample of 223 children with ADHD, aged 5 to 14 years, was examined with the Child Behavior Checklist (CBCL). In addition, comorbid psychiatric disorders, psychosocial risk factors, and socioeconomic status were assessed.

RESULTS

Cluster analysis of CBCL subscales yielded a solution with four distinct subgroups. While "externalizers" showed a high rate of comorbid oppositional defiant disorder (ODD) and conduct disorder (CD), "obsessive-compulsives" exhibited thought problems, low rates of comorbid CD, and high symptoms of inattention. "High psychiatric symptom carriers" had high rates of familial risk factors, acute life events, comorbid ODD, and CD. "Low psychiatric symptom carriers" also scored low in all other variables studied.

CONCLUSION

Children with ADHD can be divided into four subgroups according to their CBCL-based psychopathology, and these subgroups differ in their risk factor profiles.

Attention-deficit/hyperactivity disorder dimensionality: the reliable 'g' and the elusive 's' dimensions

The best structural model for attention-deficit/hyperactivity disorder (ADHD) symptoms remains a matter of debate. The objective of this study is to test the fit and factor reliability of competing models of the dimensional structure of ADHD symptoms in a sample of randomly selected and high-risk children and pre-adolescents from Brazil. Our sample comprised 2512 children aged 6-12 years from 57 schools in Brazil. The ADHD symptoms were assessed using parent report on the development and well-being assessment (DAWBA). Fit indexes from confirmatory factor analysis were used to test unidimensional, correlated, and bifactor models of ADHD, the latter including "g" ADHD and "s" symptom domain factors. Reliability of all models was measured with omega coefficients. A bifactor model with one general factor and three specific factors (inattention, hyperactivity, impulsivity) exhibited the best fit to the data, according to fit indices, as well as the most consistent factor loadings. However, based on omega reliability statistics, the specific inattention, hyperactivity, and impulsivity dimensions provided very little reliable information after accounting for the reliable general ADHD factor. Our study presents some psychometric evidence that ADHD specific ("s") factors might be unreliable after taking common ("g" factor) variance into account. These results are in accordance with the lack of longitudinal stability among subtypes, the absence of dimension-specific molecular genetic findings and non-specific effects of treatment strategies. Therefore, researchers and clinicians might most effectively rely on the "g" ADHD to characterize ADHD dimensional phenotype, based on currently available symptom items.

Dispositional Trait Types of ADHD in Young Children

OBJECTIVE

This study evaluated a novel person-centered approach to parsing ADHD heterogeneity using dispositional traits.

METHOD

Participants were one hundred nine 3- to 6-year-olds, and their primary caregivers and day care providers/teachers who completed a multi-informant diagnostic procedure with longitudinal follow-up.

RESULTS

Based on latent profile analysis, young children with ADHD could be divided into low control, high surgency, and high negative affect subgroups. The low control and high surgency groups exhibited increased parent- and teacher-rated hyperactive-impulsive and oppositional-defiant disorder (ODD) symptoms. Although the low control group exhibited the worst response inhibition, the high surgency group exhibited the worst working memory. Furthermore, the high surgency group exhibited high aggression and increasing levels of hyperactivity-impulsivity and ODD symptoms over time.

CONCLUSION

A subgroup of young children with ADHD with high surgency may be at particular risk for comorbid psychopathology and longitudinal worsening of symptoms.

The Network Structure of Symptoms of the Diagnostic and Statistical Manual of Mental Disorders

Although current classification systems have greatly contributed to the reliability of psychiatric diagnoses, they ignore the unique role of individual symptoms and, consequently, potentially important information is lost. The network approach, in contrast, assumes that psychopathology results from the causal interplay between psychiatric symptoms and focuses specifically on these symptoms and their complex associations. By using a sophisticated network analysis technique, this study constructed an empirically based network structure of 120 psychiatric symptoms of twelve major DSM-IV diagnoses using cross-sectional data of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC, second wave; N = 34,653). The resulting network demonstrated that symptoms within the same diagnosis showed differential associations and indicated that the strategy of summing symptoms, as in current classification systems, leads to loss of information. In addition, some symptoms showed strong connections with symptoms of other diagnoses, and these specific symptom pairs, which both concerned overlapping and non-overlapping symptoms, may help to explain the comorbidity across diagnoses. Taken together, our findings indicated that psychopathology is very complex and can be more adequately captured by sophisticated network models than current classification systems. The network approach is, therefore, promising in improving our understanding of psychopathology and moving our field forward.

Latent profile analysis of neuropsychological measures to determine preschoolers' risk for ADHD

BACKGROUND

Hyperactive/Inattentive preschool children show clear evidence of neuropsychological dysfunction. We examined whether patterns and severity of test scores could reliably identify subgroups of preschoolers with differential risk for ADHD during school-age.

METHOD

Typically developing (TD: n = 76) and Hyperactive/Inattentive (HI: n = 138) 3-4 year olds were assessed annually for 6 years (T1-T6). Latent profile analysis (LPA) was used to form subgroups among the HI group based on objective/neuropsychological measures (NEPSY, Actigraph and Continuous Performance Test). Logistic regression assessed the predictive validity of empirically formed subgroups at risk for ADHD diagnosis relative to the TD group and to each other from T2 to T6.

RESULTS

Latent profile analysis yielded two subgroups of HI preschoolers: (a) selectively weak Attention/Executive functions, and (b) pervasive neuropsychological dysfunction across all measures. Both subgroups were more likely to have ADHD at all follow-up time-points relative to the TD group (OR range: 11.29-86.32), but there were no significant differences between the LPA-formed subgroups of HI children at any time-point.

CONCLUSIONS

Objective/neuropsychological measures distinguish HI preschoolers from their TD peers, but patterns and severity of neuropsychological dysfunction do not predict risk for ADHD during school-age. We hypothesize that trajectories in at-risk children are influenced by subsequent environmental and neurodevelopmental factors, raising the possibility that they are amenable to early intervention.

[Formula: see text]Differences in memory functioning between children with attention-deficit/hyperactivity disorder and/or focal epilepsy

Prior research has shown that attention-deficit/hyperactivity disorder (ADHD) and epilepsy are frequently comorbid and that both disorders are associated with various attention and memory problems. Nonetheless, limited research has been conducted comparing the two disorders in one sample to determine unique versus shared deficits. Hence, we investigated differences in working memory (WM) and short-term and delayed recall between children with ADHD, focal epilepsy of mixed foci, comorbid ADHD/epilepsy and controls. Participants were compared on the Core subtests and the Picture Locations subtest of the Children's Memory Scale (CMS). Results indicated that children with ADHD displayed intact verbal WM and long-term memory (LTM), as well as intact performance on most aspects of short-term memory (STM). They performed worse than controls on Numbers Forward and Picture Locations, suggesting problems with focused attention and simple span for visual-spatial material. Conversely, children with epilepsy displayed poor focused attention and STM regardless of the modality assessed, which affected encoding into LTM. The only loss over time was found for passages (Stories). WM was intact. Children with comorbid ADHD/epilepsy displayed focused attention and STM/LTM problems consistent with both disorders, having the lowest scores across the four groups. Hence, focused attention and visual-spatial span appear to be affected in both disorders, whereas additional STM/encoding problems are specific to epilepsy. Children with comorbid ADHD/epilepsy have deficits consistent with both disorders, with slight additive effects. This study suggests that attention and memory testing should be a regular part of the evaluation of children with epilepsy and ADHD.