Executive functions in girls with ADHD followed prospectively into young adulthood

A systematic review of the utility of continuous performance tests among adults with ADHD

OBJECTIVE

The clinical utility of continuous performance tests (CPTs) among adults with attention-deficit/hyperactivity disorder (ADHD) has increasingly been brought under question. Therefore, the objective of this study was to systematically review the literature to investigate the clinical utility of various commercially available CPTs, including the Conner's Continuous Performance Test (CCPT), Test of Variables of Attention (TOVA), Gordon Diagnostic System (GDS), and Integrated Visual and Auditory Continuous Performance Test (IVA) in the adult ADHD population.

METHODS

This systematic review followed the a priori PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Articles were gathered from PsycINFO, PsycARTICLES, Academic Search Complete, and Google Scholar on 11 April 2022. Sixty-nine articles were included in the final review. Risk of bias was assessed using the National Institute of Health Quality Assessment Took for Observational Cohort and Cross-Sectional Studies.

RESULTS

Most articles demonstrated high risk of bias, and there was substantial heterogeneity across studies. Overall, the reviewed CPTs appeared to have limited diagnostic utility and classification accuracy. Although many studies showed differing scores between adults with ADHD and comparison groups, findings were not consistent. Characteristics of CPT performances among adults with ADHD were mixed, with little consistency and no evidence of a clear profile of performances; however, CCPT commission errors appeared to have the most utility when used a treatment or experimental outcome measure, compared to other CCPT scores.

CONCLUSION

Overall, CPTs should not be used in isolation as a diagnostic test but may be beneficial when used as a component of a comprehensive assessment.

Assessment of ADHD Subtypes Using Motion Tracking Recognition Based on Stroop Color-Word Tests

Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder known for its significant heterogeneity and varied symptom presentation. Describing the different subtypes as predominantly inattentive (ADHD-I), combined (ADHD-C), and hyperactive-impulsive (ADHD-H) relies primarily on clinical observations, which can be subjective. To address the need for more objective diagnostic methods, this pilot study implemented a Microsoft Kinect-based Stroop Color-Word Test (KSWCT) with the objective of investigating the potential differences in executive function and motor control between different subtypes in a group of children and adolescents with ADHD. A series of linear mixture modeling were used to encompass the performance accuracy, reaction times, and extraneous movements during the tests. Our findings suggested that age plays a critical role, and older subjects showed improvements in KSWCT performance; however, no significant divergence in activity level between the subtypes (ADHD-I and ADHD-H/C) was established. Patients with ADHD-H/C showed tendencies toward deficits in motor planning and executive control, exhibited by shorter reaction times for incorrect responses and more difficulty suppressing erroneous responses. This study provides preliminary evidence of unique executive characteristics among ADHD subtypes, advances our understanding of the heterogeneity of the disorder, and lays the foundation for the development of refined and objective diagnostic tools for ADHD.

Genomic patterns linked to gray matter alterations underlying working memory deficits in adults and adolescents with attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable neurodevelopmental disorder, with onset in childhood and a considerable likelihood to persist into adulthood. Our previous work has identified that across adults and adolescents with ADHD, gray matter volume (GMV) alteration in the frontal cortex was consistently associated with working memory underperformance, and GMV alteration in the cerebellum was associated with inattention. Recent knowledge regarding ADHD genetic risk loci makes it feasible to investigate genomic factors underlying these persistent GMV alterations, potentially illuminating the pathology of ADHD persistence. Based on this, we applied a sparsity-constrained multivariate data fusion approach, sparse parallel independent component analysis, to GMV variations in the frontal and cerebellum regions and candidate risk single nucleotide polymorphisms (SNPs) data from 341 unrelated adult participants, including 167 individuals with ADHD, 47 unaffected siblings, and 127 healthy controls. We identified one SNP component significantly associated with one GMV component in superior/middle frontal regions and replicated this association in 317 adolescents from ADHD families. The association was stronger in individuals with ADHD than in controls, and stronger in adults and older adolescents than in younger ones. The SNP component highlights 93 SNPs in long non-coding RNAs mainly in chromosome 5 and 21 protein-coding genes that are significantly enriched in human neuron cells. Eighteen identified SNPs have regulation effects on gene expression, transcript expression, isoform percentage, or methylation level in frontal regions. Identified genes highlight MEF2C, CADM2, and CADPS2, which are relevant for modulating neuronal substrates underlying high-level cognition in ADHD, and their causality effects on ADHD persistence await further investigations. Overall, through a multivariate analysis, we have revealed a genomic pattern underpinning the frontal gray matter variation related to working memory deficit in ADHD.

Understanding patterns of heterogeneity in executive functioning during adolescence: Evidence from population-level data

Executive functioning (EF) is fundamental to positive development. Yet, little is known about how to best characterize constellations of EF skills that may inform disparate associations between EF and behavior during adolescence. In the current study, cross-validated latent profile analysis (LPA) was used to derive profiles of EF based on measures of inhibitory control, working memory, and cognitive flexibility using data from 11,672 youth (52.2% male, mean age = 9.91 years) in the Adolescent Brain and Cognitive Development study. Four meaningful EF profiles emerged from the data representing Average EF, High EF, Low Inhibitory Control, and Low EF. Boys, youth from low-income households, and early developing youth were more likely to be in profiles distinguished by lower EF. Profile membership also predicted differences in externalizing, internalizing, and other problem behaviors assessed one year later. Findings indicate that youth may have distinct constellations of EF skills, underscoring the need for person-centered approaches that focus on patterns of individual characteristics.

Body Mass Indices of Girls with and without ADHD: Developmental Trajectories from Childhood to Adulthood

OBJECTIVE

We examined the predictive relation between childhood-diagnosed ADHD and trajectories of body mass index (BMI) from childhood to adulthood in an all-female sample, accounting for socioeconomic status (SES), childhood comorbidities (e.g., depression/anxiety), and stimulant usage. Childhood executive functioning (i.e., planning, sustained attention, and response inhibition) was also evaluated as a possible predictor of BMI trajectories.

METHOD

We utilized longitudinal data from a full sample of 140 girls diagnosed with ADHD in childhood and 88 comparison girls matched on age and ethnicity. Girls were 6-12 years old at the first assessment and followed prospectively for 16 years. Data were collected on their BMI and stimulant medication usage across four evaluation waves. Using latent growth curve modeling, we evaluated the BMI trajectories of girls with ADHD and the comparison sample from childhood to adulthood.

RESULTS

Although there was no significant difference in initial childhood BMI, girls with ADHD increased in BMI at a significantly faster rate than comparison girls across development, even when adjusting for covariates. Significant differences in BMI first emerged in adolescence; by adulthood, 40.2% of the ADHD sample met criteria for obesity versus 15.4% of the comparison sample. When covarying ADHD diagnosis, executive functioning measures were not significantly predictive of BMI increase. Adjusting for stimulant medication usage within the ADHD sample did not alter core findings.

CONCLUSIONS

We discuss health-related implications for girls with ADHD, potential underlying mechanisms, and how our findings may inform both ADHD and obesity interventions.

The impact of childhood deprivation on adult neuropsychological functioning is associated with ADHD symptom persistence

BACKGROUND

Institutional deprivation in early childhood is associated with neuropsychological deficits in adolescence. Using 20-year follow-up data from a unique natural experiment - the large-scale adoption of children exposed to extreme deprivation in Romanian institutions in the 1980s -we examined, for the first time, whether such deficits are still present in adulthood and whether they are associated with deprivation-related symptoms of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD).

METHODS

Adult neuropsychological functioning was assessed across five domains (inhibitory control, emotion recognition, decision-making, prospective memory and IQ) in 70 previously institutionalized adoptees (mean age = 25.3, 50% female) and 22 non-deprived UK adoptees (comparison group, mean age = 24.6, 41% female). ADHD and ASD symptoms were assessed using parent-completed questionnaires.

RESULTS

Early institutionalization was associated with impaired performance on all tasks in adulthood. Prospective memory deficits persisted after controlling for IQ. ADHD and ASD symptoms were positively correlated. After controlling for ASD symptoms, ADHD symptoms remained associated with deficits in IQ, prospective memory, proactive inhibition, decision-making quality and emotion recognition. ASD symptoms were not independently associated with neuropsychological deficits when accounting for their overlap with ADHD symptoms. Multiple regression analysis revealed that the link between childhood deprivation and adult ADHD symptoms was statistically explained by deprivation-related differences in adult IQ and prospective memory.

CONCLUSIONS

These results represent some of the most compelling evidence to date of the enduring power of early, time-limited childhood adversity to impair long-term neuropsychological functioning across the lifespan - effects that are linked specifically to deprivation-related adult ADHD symptoms.

The Effects of Family Transitions on Depressive Symptoms: Differences among Young Adults with and without Childhood Symptoms of Attention-Deficit/ Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is tied to higher levels of depression, but the social factors that shape these associations are not well understood. This study considers whether family transitions affect depressive symptoms differently for young adults with and without childhood symptoms of ADHD at subthreshold or diagnostic levels. Between-within regression analysis of nationally representative longitudinal survey data shows that transitions into cohabitation and parenthood affect depressive symptoms differently for young adults with and without childhood symptoms of ADHD. Specifically, within-person effects indicate that transitions into cohabitation and parenthood are tied to decreases in depressive symptoms, but only for young adults without childhood symptoms of ADHD. In contrast, transitions into marriage are tied to decreases in depressive symptoms, and transitions out of coresidential unions are tied to increases in depressive symptoms, regardless of childhood symptoms of ADHD. The results suggest that some family transitions may work to widen ADHD disparities in depression, under-scoring the importance of family contexts for shaping mental health throughout the life course.

Longitudinal Trajectories of Sustained Attention Development in Children and Adolescents with ADHD

The present study characterizes changes in sustained attention ability over ages 9-14, and whether longitudinal trajectories of attention development differ between persistent ADHD, remitted ADHD and control groups. The Sustained Attention to Response Task (SART) was administered to 120 children with ADHD and 123 controls on three occasions between ages 9 and 14. Trajectories of sustained attention development, indicated by changes in SART performance (standard deviation of response time [SDRT], omission errors, and ex-Gaussian parameters sigma and tau), were examined using generalized additive mixed models. For all measures there was a significant main effect of age; response time variability and number of omission errors improved linearly as children aged. However, children with ADHD had significantly greater SDRT, tau and omission errors than controls across waves. There were no significant group differences in sigma, indicating that the greater overall response time variability (SDRT) observed in ADHD was likely driven by more intermittent long responses (larger tau). Trajectories of sustained attention performance did not differ between children with persistent ADHD or ADHD in remission. Longitudinal trajectories of sustained attention development are comparable between ADHD and controls, however children with ADHD (regardless of remission status) display a performance deficit equivalent to typical controls 1-3 years younger. Findings highlight the need for continued clinical support for children in remission from ADHD and provide support for tau as an endophenotype of ADHD.

The Course of Neurocognitive Functioning and Prediction of Behavioral Outcome of ADHD Affected and Unaffected Siblings

Longitudinal studies on the course of neurocognitive functioning of children with ADHD and their unaffected siblings are scarce. Also, it is unclear to what extent that course is related to ADHD outcomes. A carefully phenotyped large sample of 838 Caucasian participants (ADHD-combined type: n = 339, unaffected siblings: n = 271, controls: n = 228; mean age at baseline = 11.4 years, mean age at follow-up = 17.3 years, SD = 3.2) was used to investigate differences in the course of neurocognitive functioning of ADHD affected and unaffected siblings versus controls, and to investigate the relationship between neurocognitive change and ADHD outcomes. At baseline, an aggregated measure of overall neurocognitive functioning and eight neurocognitive measures of working memory, timing (speed/variability), motor control, and intelligence were investigated. Outcomes at follow-up were dimensional measures of ADHD symptom severity and the Kiddie-Global Assessment Scale (K-GAS) for overall functioning. At follow up, affected and unaffected siblings trended to, or fully caught up with performance levels of controls on four (44.4%) and five (55.6%) of the nine dependent variables, respectively. In contrast, performance in remaining key neurocognitive measures (i.e. verbal working memory, variability in responding) remained impaired at follow-up. Change in neurocognitive functioning was not related to ADHD outcomes. Our results question the etiological link between neurocognitive deficits and ADHD outcomes in adolescents and young adults.

Childhood Social Functioning and Young Adult Intimate Partner Violence in Girls With and Without ADHD: Response Inhibition as a Moderator

Objective: Examine the moderating effects of response inhibition on the longitudinal association between social preference/relational aggression measured in childhood, and intimate partner violence (IPV) measured in young adulthood, among women with (n = 140) and without (n = 88) histories of childhood ADHD. Method: During childhood, social preference was measured through confidential peer sociometric nominations, yielding negative and positive peer regard; relational aggression was assessed via staff behavioral observations; and response inhibition was assessed using commission errors from the continuous performance task. During young adulthood, IPV was ascertained via a clinician-administered, semistructured interview. Results: Social preference and relational aggression independently predicted IPV; this prospective link was moderated by response inhibition. Conclusion: In combination with low social preference or high relational aggression in childhood, poor response inhibition predicted the highest levels of young-adult IPV. Given the developmental significance of peer relationships, additional research on the causes of and treatments for poor social functioning in ADHD is warranted.

Neuropsychological Performance Patterns of Adult ADHD Subtypes

Objective: Neuropsychological performance patterns associated with adult ADHD subtypes are unknown. The aim of the current systematic review was to identify and synthesize available literature regarding neuropsychological performance associated with adult ADHD subtypes. Method: Searches were completed using the databases PsycINFO and PubMed for studies published before March 2017 addressing adult ADHD subtypes and neuropsychological performance. Data characterizing the neuropsychological tests utilized in each study were obtained and sorted into eight domains. To summarize the results of all comparisons (ADHD subtype compared with control, or to each other), we counted the proportion of tests within each domain with significant group differences. Results/Conclusion: We deemed four domains informative in differentiating ADHD subtypes from controls. Of these, memory was the only domain that held promise in distinguishing ADHD-Inattentive and ADHD-Combined. Limitations of the available literature are highlighted and recommendations for future research are provided.

Executive Functions in Girls With and Without Childhood ADHD Followed Through Emerging Adulthood: Developmental Trajectories

Using an all-female sample, we examined trajectories of executive functioning (EF) performance from childhood through emerging adulthood-and their prediction of key emerging-adult outcomes. One hundred forty girls carefully diagnosed with attention deficit/hyperactivity disorder (ADHD) and 88 matched comparison girls were administered EF measurements assessing global EF, response inhibition, and verbal working memory during childhood (M age = 9.5 years), adolescence (M age = 14.1 years), the earliest years of adulthood (M age = 19.6 years), and the end of emerging adulthood (M age = 25.6 years). Retention rates were excellent. Hierarchical linear modeling was used to estimate growth curves for each EF measure. The linear EF slopes were then used to explore how changes in EF interacted with each participant's persistence/remission of ADHD over time to influence behavioral, emotional, and academic impairment in emerging adulthood. Although all women experienced absolute improvements in EF performance across time, women with histories of ADHD consistently lagged behind comparison women, even if their ADHD symptoms had remitted by early adulthood. However, EF performance over time did not significantly influence the link between ADHD status and (a) maternal reports of associated behavioral and emotional impairment or (b) objective measures of academic achievement. These findings indicate that EF deficits should be considered when developing and implementing treatments for ADHD through emerging adulthood. Future research should be aimed at understanding the mechanisms behind these observed trajectory differences.

Assessing Impairment in Childhood ADHD: Validation of the Parent and Teacher ADHD-FX Rating Scale in a Dual-Site Clinical Sample

OBJECTIVE

The current study sought to establish psychometric properties of the ADHD-FX (a culturally sensitive measure designed to assess functional impairment related to ADHD) in a dual-site clinical sample.

METHOD

We analyzed patient charts of 67 children (47 boys and 20 girls, ages 5 to 15 years) receiving comprehensive assessments from two university-based ADHD clinics.

RESULTS

The parent and teacher ADHD-FX rating scales demonstrated good psychometric properties via adequate reliability (Cronbach's α > .70), convergent construct validity (significant correlations with majority of theoretically related measures), and divergent construct validity (insignificant correlations with majority of theoretically unrelated measures).

CONCLUSION

Results extend upon previously published psychometric analyses to suggest that the ADHD-FX is a reliable and valid measure for parents and teachers to assess functional impairment related to ADHD (i.e., difficulties with academic achievement, social competence, and familial relationships) in community and clinical populations. Clinical implications and future directions are discussed.

Learning Process During Risk Detection in Adolescents With ADHD

OBJECTIVE

To evaluate and describe the performance during the learning process of risk-detection versus risk-benefit processing in adolescents diagnosed with ADHD.

METHOD

Thirty-five adolescents with ADHD and 26 paired controls participated. The tests applied are Iowa-type children version paradigm and Stroop test.

RESULTS

Adolescents with ADHD exhibited lower risk-benefit processing capacity and lower ability to detect risk selections; main findings also indicate that adolescents with ADHD were slower to learn to avoid risk choices. In addition, they also presented a deficient inhibitory control.

CONCLUSION

Results confirm the presence of a deficit in advantageous choice in adolescents with ADHD. By providing a measure of risk choice-and not only a net score-we show that adolescents with ADHD also fail to avoid risk choices. This deficit is mainly because they are slower in learning how to avoid risk choices, and not simply deficient. Literature is scarce concerning studies with Iowa-type paradigms in samples intregated exclusively by adolescents. More research is needed to clarify the nature of these deficiencies.

Childhood-Diagnosed ADHD, Symptom Progression, and Reversal Learning in Adulthood

OBJECTIVE

ADHD persists in up to 60% into adulthood, and the reasons for persistence are not fully understood. The objective of this study was to characterize the neurofunctional basis of decision making in those with a childhood diagnosis of ADHD with either persistent or remitted symptoms in adulthood versus healthy control participants.

METHOD

Thirty-two adults diagnosed with ADHD as children were split into persistent ( n = 18) or remitted ( n = 14) ADHD groups. Their neural activity and neurofunctional connectivity during a probabilistic reversal learning task were compared with 32 healthy controls.

RESULTS

Remitters showed significantly higher neural connectivity in final reversal error and probabilistic error conditions, and persisters depict higher neural connectivity in reversal errors than controls at a family-wise error (FWE) corrected whole-brain corrected threshold.

CONCLUSION

Remitters may have utilized higher neural connectivity than controls to make successful decisions. Also, remitters may have utilized compensatory strategies to override any potential underlying ADHD deficits.

Attention Deficit Hyperactivity Disorder (ADHD): Controversy, Developmental Mechanisms, and Multiple Levels of Analysis

Controversy abounds regarding the symptom dimensions of attention problems, impulsivity, and hyperactivity, developmentally extreme and impairing levels of which compose the diagnostic category of attention deficit hyperactivity disorder (ADHD). I highlight causal factors, underlying mechanisms, developmental trajectories, and female manifestations of ADHD, integrating the psychobiological underpinnings of this syndrome with contextual factors related to its clinical presentation, impairments, and soaring increases in diagnosed prevalence. Indeed, despite strong heritability, ADHD is expressed via transactional patterns of influence linked to family-, school-, peer-, neighborhood-, and policy-related factors. Moreover, intervention strategies must take into account both pharmacologic and behavioral modalities if the goal is to enhance competencies, rather than symptom reduction per se. A comprehensive understanding of ADHD mandates multiple levels of analysis-spanning genes, neurotransmission, brain pathways, individual skill levels, family socialization, peer relationships, and educational and cultural forces-which must be integrated and synthesized to surpass reductionist accounts, reduce stigma, and maximize the impact of prevention- and intervention-related efforts.

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.

Fractionating Executive Functions of Adults With ADHD

OBJECTIVE

To evaluate the performance of adults with ADHD considering the fractionation of executive functions into six different domains.

METHOD

Participants were adult ADHD patients who were not under the acute effects of medication ( n = 48). Their performance was compared with that of a healthy control group ( n = 20) of comparable age, education, and nonverbal intelligence quotient. The cognitive domains assessed were executive shifting, updating, inhibition of prepotent responses, dual-task performance, planning, and access to long-term memory. We also assessed the symptoms of inattention, hyperactivity/impulsivity, anxiety, and depression by validated questionnaires.

RESULTS

Compared with controls, patients reported more symptoms related to ADHD, anxiety and depression symptoms and were impaired in the shifting cost measure and phonemic fluency (measure of access to long-term memory).

CONCLUSION

ADHD in adults selectively impaired executive shifting and access to long-term memory, domains that may alter performance in a wide range of daily tasks.

Changing ASD-ADHD symptom co-occurrence across the lifespan with adolescence as crucial time window: Illustrating the need to go beyond childhood

Literature on the co-occurrence between Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) is strongly biased by a focus on childhood age. A review of the adolescent and adult literature was made on core and related symptoms of ADHD and ASD. In addition, an empirical approach was used including 17,173 ASD-ADHD symptom ratings from participants aged 0 to 84 years. Results indicate that ASD/ADHD constellations peak during adolescence and are lower in early childhood and old age. We hypothesize that on the border of the expected transition to independent adulthood, ASD and ADHD co-occur most because social adaptation and EF skills matter most. Lower correlations in childhood and older age may be due to more diffuse symptoms reflecting respectively still differentiating and de-differentiating EF functions. We plea for a strong research focus in adolescence which may -after early childhood- be a second crucial time window for catching-up pattern explaining more optimal outcomes. We discuss obstacles and oppportunities of a full lifespan approach into old age.

Combined Stimulant and Guanfacine Administration in Attention-Deficit/Hyperactivity Disorder: A Controlled, Comparative Study

OBJECTIVE

Because models of attention-deficit/hyperactivity disorder (ADHD) therapeutics emphasize benefits of both enhanced dopaminergic and noradrenergic signaling, strategies to enhance D1 and α2A agonism may yield enhanced clinical and cognitive responses. This study tested the hypothesis that combined effects of a dopamine and noradrenergic agonist, d-methylphenidate extended-release (DMPH) with guanfacine (GUAN), an α2A receptor agonist, would be clinically superior to either monotherapy and would have equal tolerability.

METHOD

An 8-week, double-blind, 3-arm, comparative trial randomized 7- to 14-year-olds with DSM-IV ADHD to GUAN (1-3 mg/day), DMPH (5-20 mg/day), or a combination (COMB) with fixed-flexible dosing. Outcome measures were the ADHD Rating Scale IV (ADHD-RS-IV) and the Clinical Global Impression-Improvement (CGI-I) scale. Data on adverse events and safety measures were obtained.

RESULTS

A total of 207 participants were randomized and received drug. Analyses showed significant treatment group main effects for ADHD-RS-IV ADHD total (p = .0001) and inattentive symptoms (p = .0001). COMB demonstrated small but consistently greater reductions in ADHD-RS-IV Inattentive subscale scores versus monotherapies (DMPH: p = .05; f(2) = .02; and GUAN: p = .02; f(2) = .02), and was associated with a greater positive response rate by CGI-I (p = .01). No serious cardiovascular events occurred. Sedation, somnolence, lethargy, and fatigue were greater in both guanfacine groups. All treatments were well tolerated.

CONCLUSION

COMB showed consistent evidence of clinical benefits over monotherapies, possibly reflecting advantages of greater combined dopaminergic and α2A agonism. Adverse events were generally mild to moderate, and COMB treatment showed no differences in safety or tolerability.

CLINICAL TRIAL REGISTRATION INFORMATION

Single Versus Combination Medication Treatment for Children With Attention Deficit Hyperactivity Disorder (Project1); http://clinicaltrials.gov/; NCT00429273.

Altered frontal pole development affects self-generated spatial working memory in ADHD

BACKGROUND

Spatial working memory (SWM) dysfunction is a feature of attention deficit hyperactivity disorder (ADHD). Previous studies suggested that behavioral performance in self-generated SWM improves through development in children with and without ADHD. Nevertheless, developmental changes in the neural underpinnings of self-generated SWM are unknown.

METHOD

Using near-infrared spectroscopy, hemodynamic activity in the prefrontal cortex (PFC) was measured in 30 children with ADHD (9.5 ± 1.6 years-old) and 35 TD children (9.0 ± 1.6 years-old) while they performed a self-generated SWM task. We then investigated correlations between age and behavioral performance, and between age and hemodynamic activity in the PFC for each group.

RESULTS

Both groups showed a negative correlation with age and number of errors [ADHD: r(28)=-0.37, p=0.040; TD: r(33)=-0.59, p<0.001], indicating that self-generated SWM improves through development. The TD group showed a positive correlation between age and oxygenated hemoglobin in the frontal pole [10ch: r(33)=0.41, p=0.013; 11ch; r(33)=0.44, p=0.008] and bilateral lateral PFC [4ch: r(33)=0.34, p=0.049; 13ch; r(33)=0.54, p=0.001], while no significant correlation was found in the ADHD group. Furthermore, regression slopes for the frontal pole significantly differed between the TD and ADHD groups [10ch: t(61)=2.35, p=0.021; 11ch: t(61)=2.05, p=0.044].

CONCLUSION

Children with ADHD showed abnormalities in functional maturation of the frontal pole, which plays a role in manipulating and maintaining information associated with self-generated behavior.

Common polygenic risk for autism spectrum disorder (ASD) is associated with cognitive ability in the general population

Cognitive impairment is common among individuals diagnosed with autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD). It has been suggested that some aspects of intelligence are preserved or even superior in people with ASD compared with controls, but consistent evidence is lacking. Few studies have examined the genetic overlap between cognitive ability and ASD/ADHD. The aim of this study was to examine the polygenic overlap between ASD/ADHD and cognitive ability in individuals from the general population. Polygenic risk for ADHD and ASD was calculated from genome-wide association studies of ASD and ADHD conducted by the Psychiatric Genetics Consortium. Risk scores were created in three independent cohorts: Generation Scotland Scottish Family Health Study (GS:SFHS) (n=9863), the Lothian Birth Cohorts 1936 and 1921 (n=1522), and the Brisbane Adolescent Twin Sample (BATS) (n=921). We report that polygenic risk for ASD is positively correlated with general cognitive ability (beta=0.07, P=6 × 10(-7), r(2)=0.003), logical memory and verbal intelligence in GS:SFHS. This was replicated in BATS as a positive association with full-scale intelligent quotient (IQ) (beta=0.07, P=0.03, r(2)=0.005). We did not find consistent evidence that polygenic risk for ADHD was associated with cognitive function; however, a negative correlation with IQ at age 11 years (beta=-0.08, Z=-3.3, P=0.001) was observed in the Lothian Birth Cohorts. These findings are in individuals from the general population, suggesting that the relationship between genetic risk for ASD and intelligence is partly independent of clinical state. These data suggest that common genetic variation relevant for ASD influences general cognitive ability.

Dissociation of working memory impairments and attention-deficit/hyperactivity disorder in the brain

Prevailing neuropsychological models of attention-deficit/hyperactivity disorder (ADHD) propose that ADHD arises from deficits in executive functions such as working memory, but accumulating clinical evidence suggests a dissociation between ADHD and executive dysfunctions. This study examined whether ADHD and working memory capacity are behaviorally and neurobiologically separable using functional magnetic resonance imaging (fMRI). Participants diagnosed with ADHD in childhood who subsequently remitted or persisted in their diagnosis as adults were characterized at follow-up in adulthood as either impaired or unimpaired in spatial working memory relative to controls who never had ADHD. ADHD participants with impaired spatial working memory performed worse than controls and ADHD participants with unimpaired working memory during an n-back working memory task while being scanned. Both controls and ADHD participants with unimpaired working memory exhibited significant linearly increasing activation in the inferior frontal junction, precuneus, lingual gyrus, and cerebellum as a function of working-memory load, and these activations did not differ significantly between these groups. ADHD participants with impaired working memory exhibited significant hypoactivation in the same regions, which was significantly different than both control participants and ADHD participants with unimpaired working memory. These findings support both a behavioral and neurobiological dissociation between ADHD and working memory capacity.

•

ADHD and working memory deficits were behaviorally and neurally dissociable.

•

Working memory performance was unrelated to the current ADHD diagnosis.

•

Impaired working memory was associated with reduced brain activations.

•

Working memory status was stable, while ADHD diagnostic status was more variable.

Risk and resilience in preterm children at age 6

Children born preterm are at risk for experiencing significant deleterious developmental outcomes throughout their childhood and adolescence. However, individual variation and resilience are hallmarks of the preterm population. The present study examined pathways to resilience across multiple domains (e.g., social activities, peer relations, attention-deficit/hyperactivity disorder symptomology, externalizing and internalizing behavior, and sleep quality) as children born preterm reached school age. The study also examined early child and family predictors of resilience. Using a prospective longitudinal design, 173 infants born preterm and without significant neurological complications were assessed at five time points: neonatal intensive care unit discharge, 9 months, 16 months, 24 months, and 6 years. Three pathways of adaptation emerged at 6 years: children who were resilient, those who remained at-risk, and children who exhibited significant difficulties. Resilient children were less likely to have experienced negative parenting at 9 and 16 months, more likely to delay gratification at 24 months, and more likely to experience neonatal health complications than nonresilient children.

Neurocognitive predictors of substance use disorders and nicotine dependence in ADHD probands, their unaffected siblings, and controls: a 4-year prospective follow-up

BACKGROUND

Attention-Deficit/Hyperactivity Disorder (ADHD) is a risk factor for substance use disorders (SUDs) and nicotine dependence (ND). Neurocognitive deficits may predict the increased risk of developing SUDs and nicotine dependence.

METHODS

This study comprised three groups derived from the Dutch part of the International Multicenter ADHD Genetics (IMAGE) study: ADHD probands (n = 294), unaffected siblings (n = 161), and controls (n = 214). At baseline (age = 12.2), a range of neurocognitive functions was assessed including executive functions (inhibition, working memory, timing), measures of motor functioning (motor timing and tracking) and IQ. After a mean follow-up of 4.2 years, SUDs and ND were assessed.

RESULTS

None of the neurocognitive functions predicted later SUDs or ND in ADHD probands, even after controlling for medication use and conduct disorder. Slower response inhibition predicted later nicotine dependence in unaffected siblings (OR = 2.06, 95% CI = 1.22-3.48), and lower IQ predicted increased risk for SUDs in controls (OR = 1.96, 95% CI = 1.12-3.44).

CONCLUSIONS

Cold executive functions, motor functioning, and IQ did not predict the elevated risk of SUDs and ND in ADHD. Future studies should target 'hot' executive functions such as reward processing as risk factors for SUDs or ND.

Parenting teens with attention-deficit/hyperactivity disorder: challenges and opportunities

Attention-deficit/hyperactivity disorder (ADHD) presents in childhood with inattention, hyperactivity, and impulsivity and is associated with functional impairments. These children tend to display a variety of disruptive behaviors, which may worsen in adolescence. Teens with ADHD may show high levels of defiance, posing significant challenges for parents. Early efforts to understand parenting in the context of teen ADHD reveal high levels of parental stress and reactivity in response to the teen's ADHD symptoms. Subsequent research recognized that some of these parents have ADHD or other psychopathology that may contribute to maladaptive parenting. However, some parents adjust and demonstrate optimism and resilience in the face of their teens' ADHD. Recent research has identified parental factors (eg, emotional intelligence) and interventions (eg, mindfulness training) that may improve parenting/teen relationships and the developmental outcomes of teens. This article explores parenting teens with ADHD with a focus on these novel interventions.

Executive functions in girls with and without childhood ADHD: developmental trajectories and associations with symptom change

BACKGROUND

We prospectively followed an ethnically and socioeconomically diverse sample of girls with attention-deficit/hyperactivity disorder (ADHD) (n = 140) and a matched comparison sample (n = 88) from childhood through young adulthood to evaluate developmental trajectories of executive functions (EF) and associations between EF trajectories and dimensional measures of ADHD symptoms. We hypothesized that (a) EF trajectories would be similar in girls both with and without childhood ADHD, with the ADHD group showing greater impairment across time; and (b) changes in EF abilities would predict changes in ADHD symptoms across time, consistent with the theory that ADHD symptom reductions partially result from prefrontally mediated EF development.

METHOD

Latent growth curve models were used to evaluate development of sustained attention, response inhibition, working memory, and global EF abilities, and associations between EF trajectories and ADHD symptom trajectories.

RESULTS

Girls with childhood-diagnosed ADHD showed greater improvement across development on measures of sustained attention and global EF, but similar rates of improvement on measures of working memory and response inhibition. Changes in the global EF measure predicted changes in both inattentive and hyperactive-impulsive symptoms across time, whereas changes in response inhibition predicted changes in hyperactive-impulsive symptoms; associations between changes in other EF variables and symptoms were not significant.

CONCLUSIONS

Findings suggest variability in patterns of EF improvement over time in females with ADHD histories and indicate that EF development may play a role in symptom change.

Associations of symptoms and subtypes of attention-deficit hyperactivity disorder with visuospatial planning ability in youth

Little is known about which ADHD core symptom or subtype is most associated with visuospatial planning deficit. This issue was investigated in a sample of 408 youths with current DSM-IV diagnosis of ADHD, and 332 youths without lifetime ADHD, aged 8-17 years (mean age 12.02±2.24). All the participants and their mothers were interviewed using the Chinese Kiddie Epidemiologic version of the Schedule for Affective Disorders and Schizophrenia to obtain information about ADHD symptoms and diagnosis and other psychiatric disorders. In addition to clinical assessments, the participants were assessed with the WISC-III and the Stocking of Cambridge task of the Cambridge Neuropsychological Test Automated Battery. Multi-level regression models were used for data analysis. The results showed that univariate analyses revealed that inattention, hyperactivity, and impulsivity were significantly associated with visuospatial planning, and the magnitude of such association was amplified with increased task difficulties. Only inattention independently predicted visuospatial planning in a model that included all three ADHD symptoms. After further controlling for comorbidity, age of assessment, treatment with methylphenidate, and Full-scale IQ, inattention was still independently associated with visuospatial planning indexed by mean moves needed to solve problems. In subtype comparison, participants with combined subtype and those with prominently inattentive subtype, rather than prominently hyperactivity/impulsivity subtype, had poorer visuospatial planning performance. Our findings indicate that inattention is independently associated with impaired visuospatial planning, and dimensional approach retains the important distinction among ADHD symptoms than subtype approach in understanding the neuropsychological functioning of ADHD.

The developmental trajectories of executive function of children and adolescents with Attention Deficit Hyperactivity Disorder

This study examined the developmental trajectories of executive function (EF) of children and adolescents with Attention Deficit Hyperactivity Disorder (ADHD) in Han Chinese. Five hundred and fifteen children and adolescents with ADHD and 249 healthy controls took part in this study. All of them were administered four EF tests capturing inhibition, working memory, shifting and planning components. The participants were further divided into four age groups, 7-8, 9-10, 11-12, and 13-15 years old, respectively, for developmental trajectories comparison. The performance of the typical developing children and adolescents aged 7-15 were reported to get stable at age 11-12 for inhibition, working memory and planning, and kept developing till age 13-15 for shifting. For inhibition and shifting, participants with ADHD displayed similar performance to the healthy controls who were 2 years younger whereas they did poorer than the healthy controls of their same age. And at age 13-15, such poorer performance disappeared for inhibition but maintained for shifting. No significant differences were found between participants with and without ADHD in working memory and planning across all age groups. The current findings suggested, compared with healthy controls, Han Chinese children and adolescents with ADHD displayed delayed developmental trajectories on inhibition and shifting, whereas they showed similar trend of development on working memory and planning.

Association between early attention-deficit/hyperactivity symptoms and current verbal and visuo-spatial short-term memory

Deficits in short-term memory are common in adolescents with attention-deficit/hyperactivity disorder (ADHD), but their current ADHD symptoms cannot well predict their short-term performance. Taking a developmental perspective, we wanted to clarify the association between ADHD symptoms at early childhood and short-term memory in late childhood and adolescence. The participants included 401 patients with a clinical diagnosis of DSM-IV ADHD, 213 siblings, and 176 unaffected controls aged 8-17 years (mean age, 12.02 ± 2.24). All participants and their mothers were interviewed using the Chinese Kiddie Epidemiologic version of the Schedule for Affective Disorders and Schizophrenia to obtain information about ADHD symptoms and other psychiatric disorders retrospectively, at an earlier age first, then currently. The participants were assessed with the Wechsler Intelligence Scale for Children--3rd edition, including Digit Span, and the Spatial working memory task of the Cambridge Neuropsychological Test Automated Battery. Multi-level regression models were used for data analysis. Although crude analyses revealed that inattention, hyperactivity, and impulsivity symptoms significantly predicted deficits in short-term memory, only inattention symptoms had significant effects (all p<0.001) in a model that included all three ADHD symptoms. After further controlling for comorbidity, age of assessment, treatment with methylphenidate, and Full-scale IQ, the severity of childhood inattention symptoms was still significantly associated with worse verbal (p = 0.008) and spatial (p ranging from 0.017 to 0.002) short-term memory at the current assessment. Therefore, our findings suggest that earlier inattention symptoms are associated with impaired verbal and visuo-spatial short-term memory at a later development stage. Impaired short-term memory in adolescence can be detected earlier by screening for the severity of inattention in childhood.

Prospective follow-up of girls with attention-deficit/hyperactivity disorder into early adulthood: continuing impairment includes elevated risk for suicide attempts and self-injury

OBJECTIVE

We performed a 10-year prospective follow-up of a childhood-ascertained (6-12 years), ethnically and socioeconomically diverse sample of girls with attention-deficit/hyperactivity disorder (ADHD; N = 140: combined type [ADHD-C] n = 93; inattentive type [ADHD-I] n = 47) plus a matched comparison group (N = 88). Girls were recruited from schools, mental health centers, pediatric practices, and via advertisements; extensive evaluations confirmed ADHD versus comparison status.

METHOD

Ten-year outcomes (age range 17-24 years; retention rate = 95%) included symptoms (ADHD, externalizing, internalizing), substance use, eating pathology, self-perceptions, functional impairment (global, academic, service utilization), self-harm (suicide attempts, self-injury), and driving behavior.

RESULTS

Participants with childhood-diagnosed ADHD continued to display higher rates of ADHD and comorbid symptoms, showed more serious impairment (both global and specific), and had higher rates of suicide attempts and self-injury than the comparison sample, with effect sizes from medium to very large; yet the groups did not differ significantly in terms of eating pathology, substance use, or driving behavior. ADHD-C and ADHD-I types rarely differed significantly, except for suicide attempts and self-injury, which were highly concentrated in ADHD-C. Domains of externalizing behavior, global impairment, service utilization, and self-harm (self-injury and suicide attempts) survived stringent control of crucial childhood covariates (age, demographics, comorbidities, IQ).

CONCLUSIONS

Girls with childhood ADHD maintain marked impairment by early adulthood, spreading from symptoms to risk for serious self-harm. Our future research addresses the viability of different diagnostic conceptions of adult ADHD and their linkages with core life impairments.