Genetic associations between the symptoms of attention-deficit/hyperactivity disorder and emotional lability in child and adolescent twins

Incremental Validity of Trait Impulsivity, Dysfunctional Emotional Regulation, and Affect Lability in the Predictions of Attention Deficit Hyperactivity Disorder and Oppositional Defiant Disorder Symptoms in Adults

Difficulties in emotion regulation (DER) is a defining feature of attention deficit hyperactivity disorder (ADHD), and arguments are being made for it to be considered as a defining feature of oppositional defiant disorder (ODD). However, the consensus is that it is better viewed as an important correlate distinct from ADHD. This study examined the incremental validity of DER over and above trait impulsivity (TI) in the predictions of ADHD and ODD symptoms. It also examined the incremental validity of affect lability (AL) over and above TI and (DER) in these predictions. Five hundred and twenty-five adults from the general community completed a series of questionnaires. A model-based SEM approach for evaluating incremental validity indicated that TI predicted ADHD and ODD symptoms over age; DER predicted ADHD and ODD symptoms over age and TI; and AL did not predict ADHD and ODD symptoms over and above age, IT, or DER. In addition, AL predicted ADHD and ODD symptoms over age and TI, and DER also predicted ADHD and ODD symptoms over and above age, TI, and AL. In conclusion, TI is core to ADHD, and although DER is important, it is unlikely to be relevant as a diagnostic indicator for ADHD or ODD. These findings notwithstanding, there is need for caution when interpreting our findings, as the study did not control for potentially influencing factors on emotional regulation such as age, gender, culture, and existing psychopathologies.

Irritability in Youths: A Critical Integrative Review

Irritability, defined as proneness to anger that may impair an individual's functioning, is common in youths. There has been a recent upsurge in relevant research. The authors combine systematic and narrative review approaches to integrate the latest clinical and translational findings and provide suggestions for addressing research gaps. Clinicians and researchers should assess irritability routinely, and specific assessment tools are now available. Informant effects are prominent, are stable, and vary by age and gender. The prevalence of irritability is particularly high among individuals with attention deficit hyperactivity disorder, autism spectrum disorder, and mood and anxiety disorders. Irritability is associated with impairment and suicidality risk independent of co-occurring diagnoses. Developmental trajectories of irritability (which may begin early in life) have been identified and are differentially associated with clinical outcomes. Youth irritability is associated with increased risk of anxiety, depression, behavioral problems, and suicidality later in life. Irritability is moderately heritable, and genetic associations differ based on age and comorbid illnesses. Parent management training is effective for treating psychological problems related to irritability, but its efficacy in treating irritability should be tested rigorously, as should novel mechanism-informed interventions (e.g., those targeting exposure to frustration). Associations between irritability and suicidality and the impact of cultural context are important, underresearched topics. Analyses of large, diverse longitudinal samples that extend into adulthood are needed. Data from both animal and human research indicate that aberrant responses to frustration and threat are central to the pathophysiology of irritability, revealing important translational opportunities.

The impact of emotional dysregulation and comorbid depressive symptoms on clinical features, brain arousal, and treatment response in adults with ADHD

Introduction

The role of emotional dysregulation (ED) in attention-deficit/hyperactivity disorder (ADHD) has become an important issue. This study, in which we analyzed data from a predictive pharmaco-EEG-trial, aimed to examine whether symptoms of ED in adult ADHD affect ADHD symptom severity, brain arousal regulation as measured by resting EEG, and the response to stimulant medication.

Methods

ED is defined as having a sex- and age-corrected T-score of >70 on the emotional lability subscale of the German version of Conners' Adult ADHD Rating Scale. A total of 115 participants were included in the study, 56 of whom had ED. Participants with ED were more impaired in terms of the severity of core ADHD symptoms, especially inattentive symptoms, comorbid depressive symptoms, interpersonal relationships, and quality of life. In addition, participants with ED were more likely to report a total score above 13 on the Beck Depression Inventory-II, which was considered to be the cutoff for mild depression.

Results

No differences were found between the ED and non-ED groups in response to stimulant medication or in brain arousal regulation. In addition, there was no significant effect of ED with comorbid depressive symptoms on treatment response. There was a trend for subgroups that showed a change in brain arousal regulation associated with symptom improvement.

Discussion

Our findings may support the assumption that ED may be an important feature of ADHD. The use of EEG-based brain arousal regulation as a diagnostic and predictive tool in ADHD in the presence of ED and comorbid depressive symptoms should be further investigated.

Parsing between- and within-person effects: Longitudinal associations between irritability and internalizing and externalizing problems from early childhood through adolescence

INTRODUCTION

This report examines between- and within-person associations between youth irritability and concurrent and prospective internalizing and externalizing symptoms from early childhood through adolescence. Distinguishing between- and within-person longitudinal associations may yield distinct, clinically relevant information about pathways to multifinality from childhood irritability.

METHODS

Children's irritability and co-occurring symptoms were assessed across five waves between ages 3 and 15 years using the mother-reported Child Behavior Checklist (N = 605, 46% female). Parental history of depressive disorders was assessed with a clinical interview.

RESULTS

Results demonstrated that between- and within-person irritability were uniquely associated with concurrent depressive, anxiety, and defiance symptoms, but not ADHD. Prior wave within-person irritability also predicted next wave depressive, anxiety, and defiance symptoms, controlling for prior symptoms; these prospective associations were bidirectional. Child sex and parental depressive disorders moderated associations.

DISCUSSIONS

Findings identify pathways from within- and between-person irritability to later internalizing and externalizing psychopathology. Results demonstrate the importance of parsing within- and between-person effects to understand nuanced relations among symptoms over childhood.

Annual Research Review: Perspectives on progress in ADHD science - from characterization to cause

The science of attention-deficit/hyperactivity disorder (ADHD) is motivated by a translational goal - the discovery and exploitation of knowledge about the nature of ADHD to the benefit of those individuals whose lives it affects. Over the past fifty years, scientific research has made enormous strides in characterizing the ADHD condition and in understanding its correlates and causes. However, the translation of these scientific insights into clinical benefits has been limited. In this review, we provide a selective and focused survey of the scientific field of ADHD, providing our personal perspectives on what constitutes the scientific consensus, important new leads to be highlighted, and the key outstanding questions to be addressed going forward. We cover two broad domains - clinical characterization and, risk factors, causal processes and neuro-biological pathways. Part one focuses on the developmental course of ADHD, co-occurring characteristics and conditions, and the functional impact of living with ADHD - including impairment, quality of life, and stigma. In part two, we explore genetic and environmental influences and putative mediating brain processes. In the final section, we reflect on the future of the ADHD construct in the light of cross-cutting scientific themes and recent conceptual reformulations that cast ADHD traits as part of a broader spectrum of neurodivergence.

Emotion dysregulation in ADHD and other neurodevelopmental conditions: a co-twin control study

BACKGROUND

Emotion dysregulation (ED) is common in attention-deficit/hyperactivity disorder (ADHD) and often results in adverse outcomes. However, ED has been suggested as a transdiagnostic construct, why the specific association between ADHD and ED when adjusting for other mental health conditions needs further investigation. It is also important to determine the aetiological basis of the association between ADHD and ED to inform the theoretical conceptualization of ADHD.

METHOD

This study used a co-twin control design, including a sample of dizygotic (DZ) and monozygotic (MZ) twins (N = 389; 45.8% females, age = 8-31 years, MZ twin pairs 57.6%). ED was assessed using the dysregulation profile from the parent-rated Child Behaviour Checklist and its adult version. Regression analyses were used across individuals and within the pairs, while adjusting for diagnoses of autism, intellectual disability, other neurodevelopmental conditions and affective conditions.

RESULTS

ADHD was significantly associated with ED, even when adjusting for age, sex, attention problems and other mental health conditions, and was the diagnosis most strongly associated with ED. Within-pair analyses revealed that twins with ADHD had higher levels of ED compared to their co-twin without ADHD. This association remained within DZ twins and was non-significant in the MZ subsample, with non-overlapping confidence intervals between the DZ and MZ estimates.

CONCLUSION

ADHD is strongly and in part independently linked to ED, stressing the importance of early detection and treatment of emotional difficulties within this group. The findings from the within-pair analyses indicate a genetic influence on the association between ADHD and ED.

An inventory of European data sources to support pharmacoepidemiologic research on neurodevelopmental outcomes in children following medication exposure in pregnancy: A contribution from the ConcePTION project

BACKGROUND

Studies on medication safety in pregnancy are increasingly focusing on child neurodevelopmental outcomes. Establishing neurodevelopmental safety is complex due to the range of neurodevelopmental outcomes and the length of follow-up needed for accurate assessment. The aim of this study was to provide an inventory of European data sources for use in pharmacoepidemiologic studies investigating neurodevelopment following maternal medication exposure.

METHOD

The EUROmediSAFE inventory of data sources in Europe for evaluating perinatal and long-term childhood risks associated with in-utero exposure to medication was updated by contacting colleagues across 31 European countries, literature review and internet searches. Included data sources must record at least one neurodevelopmental outcome and maternal medication use in pregnancy must be available, either in the data source itself or through linkage with another data source. Information on the domain of neurodevelopment, measure/scale used and the approach to measurement were recorded for each data source.

RESULTS

Ninety data sources were identified across 14 countries. The majority (63.3%) were created for health surveillance and research with the remaining serving administrative purposes (21.1% healthcare databases,15.6% other administrative databases). Five domains of neurodevelopment were identified-infant development (36 data sources,13 countries), child behaviour (27 data sources, 10 countries), cognition (29 data sources, 12 countries), educational achievement (20 data sources, 7 countries), and diagnostic codes for neurodevelopmental disorders (42 data sources, 11 countries). Thirty-nine data sources, in 12 countries, had information on more than one domain of neurodevelopment.

CONCLUSION

This inventory is invaluable to future studies planning to investigate the neurodevelopmental impact of medication exposures during pregnancy. Caution must be used when combining varied approaches to neurodevelopment outcome measurement, the age of children in the data source, and the sensitivity and specificity of the outcome measure selected should be borne in mind.

Two Facets of Emotion Dysregulation Are Core Symptomatic Domains in Adult ADHD: Results from the SR-WRAADDS, a Broad Symptom Self-Report Questionnaire

OBJECTIVES

Emotional dysregulation (ED) in adult ADHD is frequent but definition and tools for its evaluation are not consensual. Our aim was to determine the core ADHD symptomatic domains via the Self-Reported Wender-Reimherr Adult Attention Deficit Disorder Scale (SR-WRAADDS) following its validation in a large clinical sample of adults with ADHD and controls.

METHOD

Three hundred sixty-nine adult patients with ADHD and 251 healthy participants completed the SR-WRAADDS and questionnaires about ADHD, depression, and ED. We analyzed the psychometric properties of the SR-WRAADDS and a factor analysis yielded symptomatic domains.

RESULTS

The SR-WRAADDS has good reliability. The 30 symptoms were best organized in a four-factor solution: attention/disorganization, hyperactivity/restlessness, impulsivity/emotional outbursts, and emotional lability.

CONCLUSIONS

The symptomatic structure of the SR-WRAADDS includes two distinct dimensions related to ED: "impulsivity/emotional outbursts" and "emotional lability." The SR-WRAADDS is a reliable and clinically useful tool that assesses all ADHD symptom domains, including facets of ED.

Adult ADHD, executive function, depressive/anxiety symptoms, and quality of life: A serial two-mediator model

BACKGROUND

Adult attention-deficit/hyperactivity disorder (ADHD) is associated with impaired executive function (EF), depressive/anxiety symptoms, and poor quality of life (QoL). In this study, we aimed to investigate correlations among these variables and to build a simple or serial mediation model for exploring the mechanisms between adult ADHD and QoL.

METHODS

This was a cross-sectional study. The sample included 223 participants with ADHD and 54 healthy volunteers. Participants were required to complete the following scales: ADHD Rating Scale (ADHD-RS), Brief Version of the World Health Organization Quality of Life Scale (WHOQOL-BREF), Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A), Self-rating Depression Scale (SDS) and Self-rating Anxiety Scale (SAS). Correlations among EF, depressive/anxiety symptoms and QoL were analyzed using Pearson correlation. The simple and serial mediation models were analyzed using PROCESS (version 3.3).

RESULTS

The correlations between EF and QoL, depressive/anxiety symptoms and QoL, and depressive/anxiety symptoms and EF were statistically significant. In ADHD adults with comorbidities, the correlation coefficients were between -0.19 and -0.47, -0.20 and -0.62, 0.28 and 0.50, respectively. In simple mediation models, EF and depressive/anxiety symptoms were significant mediators respectively between ADHD and QoL, respectively. In a serial two-mediator model, ADHD could affect QoL indirectly via EF and then via depressive/anxiety symptoms significantly.

LIMITATIONS

The average age was young, the degree of education was high, and only self-reported scales were relied on.

CONCLUSIONS

There is a mutual effect between EF and emotional symptoms. This was the first study to build a serial two-mediator model between ADHD and QoL, suggesting the importance of EF and depressive/anxiety symptoms.

Monoaminergic Genetic Variants, Prefrontal Cortex-Amygdala Circuit, and Emotional Symptoms in Children With ADHD: Exploration Based on the Gene-Brain-Behavior Relationship

Objective: This study aimed to explore the association between monoaminergic genetic variants and emotional lability (EL) symptoms in children with ADHD. In addition, genetic effects on prefrontal cortex (PFC)-amygdala functional connectivity (FC) were investigated. Method: Children with ADHD and controls were genotyped for five monoaminergic genetic variants and were evaluated for EL symptoms. Imaging genetic exploration was conducted with previously reported aberrant PFC-amygdala resting-state functional connectivities (RSFCs) as target features. Results: A genotypic effect on EL symptoms was only found for NET1-rs3785143, indicating higher EL symptoms in TT genotype carriers than in C-allele carriers. Imaging genetic analyses indicated a marginal effect of NET1-rs3785143 on ADHD-altered FC between the superficial amygdala (SFA) and middle frontal gyrus (MFG). Mediation analysis suggested potential effects of NET1-rs3785143 via RSFC (SFA-MFG) on EL. Conclusion:NET1 variants might participate in the pathogenesis of EL in children with ADHD by influencing the function of the PFC-amygdala circuit.

How and Why Are Irritability and Depression Linked?

Based on its course over time, irritability is linked to depression cross-sectionally and longitudinally. Cross-sectionally, irritability takes an episodic form as a symptom in pediatric depression; yet, irritability in the absence of depressed mood or anhedonia is rare. Longitudinally, chronic irritability has been shown to predict depression rather than bipolar disorder or externalizing disorders. Evidence suggests that the link between irritability and depression is explained mostly by shared genetic risk. Both conditions are also associated with higher rates of family history of depression, childhood temperaments and personality styles, and negative parenting styles. The treatment implications are discussed.

Integrating genomics and transcriptomics: Towards deciphering ADHD

Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable condition that represents the most common neurodevelopmental disorder in childhood, persisting into adulthood in around 40-65% of the cases. ADHD is characterised by age-inappropriate symptoms of inattention, impulsivity, and hyperactivity. Mounting evidence points towards ADHD having a strong genetic component and the first genome-wide significant findings have recently been reported. However, the functional characterization of variants unravelled by genome-wide association studies (GWAS) is challenging. Likewise, gene expression profiling studies have also been undertaken and novel integrative approaches combining genomic and transcriptomic data are starting to be conducted, which offers an exciting way that might provide a more informative insight towards the genetic architecture of ADHD. In this review, we summarised current knowledge on genomics, transcriptomics and integrative approaches in ADHD, focusing on GWAS and GWAS meta-analyses (GWAS-MA)- as genomics analyses- microarray and RNA-seq- as transcriptomics analyses-, and studies integrating genomics and transcriptomics data. In addition, current strengths and limitations of such approaches are discussed and further research avenues are proposed in order to face unsolved issues. Although important progress has been made, there is still a long way ahead to elucidate the biological mechanisms of ADHD, which eventually may lead to more personalized approaches in the future. Large- scale research efforts and new technological and statistical approaches are envisaged as important means towards deciphering ADHD in the upcoming years.

Do borderline personality disorder and attention-deficit/hyperactivity disorder co-aggregate in families? A population-based study of 2 million Swedes

Large-scale family studies on the co-occurrence of attention-deficit/hyperactivity disorder (ADHD) and borderline personality disorder (BPD) are lacking. Thus, we aimed to estimate the co-occurrence and familial co-aggregation of clinically ascertained ADHD and BPD diagnoses using the entire Swedish population. In a register-based cohort design we included individuals born in Sweden 1979-2001, and identified their diagnoses during 1997-2013; in total, 2,113,902 individuals were included in the analyses. We obtained clinical diagnoses of ADHD and BPD from inpatient and outpatient care. Individuals with an ADHD diagnosis had an adjusted (for birth year, sex, and birth order) odds ratio (aOR) of 19.4 (95% confidence interval [95% CI] = 18.6-20.4) of also having a BPD diagnosis, compared to individuals not diagnosed with ADHD. Having a sibling with ADHD also increased the risk for BPD (monozygotic twins, aOR = 11.2, 95% CI = 3.0-42.2; full siblings, aOR = 2.8, 95% CI = 2.6-3.1; maternal half-siblings, aOR = 1.4, 95% CI = 1.2-1.7; paternal half-siblings, aOR = 1.5, 95% CI = 1.3-1.7). Cousins also had an increased risk. The strength of the association between ADHD and BPD was similar in females and males, and full siblings showed similar increased risks regardless of sex. Among both males and females, ADHD and BPD co-occur within individuals and co-aggregate in relatives; the pattern suggests shared genetic factors and no robust evidence for etiologic sex differences was found. Clinicians should be aware of increased risks for BPD in individuals with ADHD and their relatives, and vice versa.

The Characteristics and Age Effects of Emotional Lability in ADHD Children With and Without Oppositional Defiant Disorder

Objective: This study evaluated the concurrent validity of emotional lability (EL) in children with ADHD. Method: A total of 2,015 children with ADHD and 745 typically developed controls (TDCs) were assessed and compared on EL. Results: ADHD participants expressed higher EL scores than TDCs, not influenced by gender or IQ. Higher levels of EL symptoms were found in children with comorbid oppositional defiant disorder (ODD) and with ADHD-combined subtype. Receiver operating characteristic (ROC) analyses showed a strong screening efficacy of EL symptoms on ADHD. The effect of developmental age on EL showed a desisting pattern in TDCs, as opposed to a persisting pattern in ADHD (not influenced by ODD comorbid status). ODD symptoms in ADHD showed an ascending pattern. Conclusion: EL can potentially serve as a sentinel index for the presence of ADHD, especially when the ADHD presentation is atypical. ODD may embody a developmental entity distinct from EL.

Neural and self-reported reward responsiveness are associated with dispositional affectivity and emotion dysregulation in adolescents with evidence for convergent and incremental validity

Adolescence is a developmental period characterized by heightened reward sensitivity which, in turn, confers risk for pertinent negative outcomes, underscoring the need to better understand biological bases and behavioral correlates of reward responsiveness during this developmental phase. Our goals in the current study were to examine, in a sample of 43 typically developing adolescents (M_age  = 15.67 years; SD = 1.01; 32.6% boys), (1) evidence of convergent validity between neural and self-report reward responsiveness, (2) associations between neural reward responsiveness and self-report dispositional affectivity and emotion dysregulation (ED) and (3) evidence of incremental validity of self-report beyond neural reward responsiveness in predicting affectivity and ED. During electroencephalography (EEG), adolescents completed two experimental paradigms probing event-related potential (ERP) indices of reward anticipation and initial responsiveness to reward attainment. Following EEG, they completed self-report measures of reward responsiveness, affectivity, and ED. Findings indicated some evidence of convergent validity between enhanced ERP indices of reward anticipation and initial response to reward and greater reinforcement sensitivity; that ERP indices of both reward responsiveness aspects predicted lower negative affectivity and less ED; and evidence of incremental validity of self-report beyond neural reward responsiveness in predicting outcomes. Results underscore the utility of a multi-method framework in assessing adolescent reward responsiveness and support the relevance of reward responsiveness in explaining individual differences in dispositional affectivity and ED.

Integrity of Amygdala Subregion-Based Functional Networks and Emotional Lability in Drug-Naïve Boys With ADHD

Objective: This study evaluated the functional networks of amygdala subregions (basolateral [BLA], centromedial [CMA], and superficial amygdala [SFA]) in ADHD and their association with emotional lability (EL) symptoms. Method: Resting-state functional connectivity (RSFC) of amygdala subregions and their correlations with EL scores were evaluated in 35 drug-naïve boys with ADHD and 30 age-matched healthy controls (HC). Results: Compared with HC, altered RSFC were detected differently for each amygdala subregion in ADHD: altered RSFC of BLA with the thalamus and vermis; aberrant RSFC of CMA with the superior temporal gyrus/pole and insula, precuneus and cerebellum; reduced RSFC of SFA with dorsal frontoparietal cortices. Within ADHD, higher EL scores were associated with reduced negative RSFC of SFA with the dorsolateral prefrontal cortex and inferior parietal lobe. Conclusion: Diffuse alterations of amygdala subregion-based networks are associated with ADHD, and the weaker SFA-frontoparietal networks might be involved in the hypothesized top-down effortful regulation of emotion.

The importance of a developmental perspective in Psychiatry: what do recent genetic-epidemiological findings show?

There is growing appreciation that a developmental perspective is helpful in Psychiatry. However, clinical practice and research, especially in an era of very large sample sizes, often ignore the developmental context. In this perspective piece, we discuss why a developmental view is important in Psychiatry and how recent genetic-epidemiological findings further highlight this. DSM-5 childhood neurodevelopmental disorders such as ADHD, typically onset in early childhood but can persist into adult life; the same ADHD genetic loading appears to contribute across the life course. However, recent longitudinal studies have observed that ADHD symptoms may emerge later during adolescence and adult life in some individuals although the etiology of this late-onset group is unclear. The epidemiology and genetics of depression do not appear to be the same in childhood, adolescence, and adult life. Recent genetic findings further highlight this. Autistic type problems and irritability also appear to show developmental variation in their genetic etiology. These findings raise the question of whether social communication and irritability have the same meaning at different ages. Schizophrenia typically onsets after adolescence. However, it is commonly preceded by childhood antecedents that do not resemble schizophrenia itself but do appear to index schizophrenia genetic liability. We conclude that there is a need for clinicians and scientists to adopt a developmental perspective in clinical practice and research by considering age-at-onset and changes over time as well as different developmental periods when interpreting clinical symptoms.

The effects of atomoxetine on emotional control in adults with ADHD: An integrated analysis of multicenter studies

Purpose:

To investigate the effects of atomoxetine on emotional control in adults with ADHD.

Methods:

We performed an integrated analysis using individual patient data pooled from three Eli Lilly-sponsored studies. An integrated analysis can be viewed as a meta-analysis of individual patient-level data, rather than study-level summary data.

Results:

Two populations were identified: a large sample of patients with pre-treatment baseline data (the “overall population”; n = 2846); and a subset of these patients with placebo-controlled efficacy data from baseline to 10 or 12 weeks after initiating treatment (the “placebo-controlled population”; n = 829). At baseline, in the overall population, ∼50% of ADHD patients had BRIEF-AS (Behavior Rating Inventory of Executive Function-Adult Version Self-Report) Emotional control subscores between 21 and 30, compared with ∼10% of normative subjects in the BRIEF-A manual. At endpoint, in the placebo-controlled population, atomoxetine led to a small (effect size 0.19) but significant (P = 0.013) treatment effect for emotional control. The effect size was 0.32 in patients with BRIEF-AS Emotional control scores > 20 at baseline. Improvements in emotional control correlated with improvements in the core ADHD symptoms and quality-of-life.

Discussion:

As deficient emotional control is associated with impaired social, educational and occupational functioning over and above that explained by core ADHD symptoms alone, improvements in emotional control may be clinically relevant.

Conclusion:

At baseline, adults with ADHD were more likely to have impaired emotional control than normative subjects. In the adult ADHD patients, atomoxetine treatment was associated with improvements in emotional control, as well as in core ADHD symptoms and quality-of-life.

Development and Application of an Innovative Transdiagnostic Treatment Approach for Pediatric Irritability

Recent work has drawn attention to the previously underrecognized role that irritability plays in childhood psychopathology. Despite increased recognition of the clinical importance of pediatric irritability as a transdiagnostic symptom dimension, there is a lack of evidence-based treatments for this population that simultaneously and equitably addresses both child and contextual (e.g., parental) factors implicated in the development and maintenance of associated emotional and behavioral difficulties. In the current pilot study, we adapted the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders in Children (UP-C) for the treatment of pediatric irritability in a sample of 19 children (ages 8 to 12) with primary presenting concerns of irritability and/or disruptive behaviors. Results supported the feasibility and acceptability of this treatment and provided preliminary evidence that such an approach may yield improved outcomes for symptoms of pediatric irritability and disruptive behaviors. Implications of these findings for future research and clinical interventions for pediatric irritability are discussed.

Genetic and environmental influences on attention-deficit/hyperactivity disorder symptoms in Chinese adolescents: a longitudinal twin study

Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable neurodevelopmental disorder. However, no study has examined genetic and environmental influences in the longitudinal developmental course of ADHD symptoms in a non-Western population. This study investigated changes of genetic and environmental influences and their contributions to the stability and change of ADHD symptoms of hyperactivity/impulsivity and inattention in Chinese adolescent twins. A prospective sample of 602 twin pairs (48% male) self-reported both DSM-IV ADHD symptom subscales three times at the approximate age of 12, 13, and 15 years. Longitudinal multivariate genetic analyses through structural equation modelling examined genetic and environmental contributions to the developmental course of ADHD symptoms. From early (time 1 and 2) to middle adolescence (time 3), both symptoms showed modest and non-significant genetic influences that became substantial and significant, whereas shared environmental influences were substantial and significant and became modest and non-significant. The same genetic factors influenced ADHD symptoms throughout adolescence, while shared and non-shared environmental influences largely came from new emerging factors. In early adolescence, genetic factor contributed to the stability of inattention, whereas shared environmental factor contributed to the stability of hyperactivity/impulsivity. Genetic influences of ADHD tended to be smaller, whereas shared environmental influences tended to be larger in Chinese than in Western populations. Genetic factors played a large role in the stability of ADHD throughout adolescence, while shared and non-shared environment primarily contributed to its change. Findings highlight the importance of shared family, neighbourhood, and community experiences on child psychopathology in a collectivistic culture such as the Chinese society.

Meta-analysis found that studies may have overestimated Caesarean section risks for attention-deficit hyperactivity disorder by ignoring confounding factors

AIM

Epidemiological studies on associations between Caesarean sections (C-sections) and attention-deficit hyperactivity disorder (ADHD) have been inconsistent, and we performed a meta-analysis.

METHODS

We systematically searched PubMed and Embase to December 2018 and included nine hospital-based and population registry studies published in 2011-2018. These covered a total study cohort of more than 2.5 million people in eight countries: Australia, Brazil, Denmark, Finland, Germany, Sweden, Turkey and the UK. The analysis provided summary odds ratios (ORs) and 95% confidence intervals (CI) while taking heterogeneity into account.

RESULTS

We found that that C-sections were associated with a small increase in the risk of ADHD (OR 1.14, 95% CI 1.11, 1.17, I² 0%) in offspring. In subgroup analyses, the association remained for both infants born after elective C-sections (OR, 1.15, 1.11, 1.19, I² 0%) and emergency C-sections (OR, 1.13, 1.1, 1.17, I² 45.4%). However, these were only marginally significant when we pooled data from siblings from other pregnancies (OR, 1.06, 1.00-1.13, I² 0%), implying that the association was due to confounding.

CONCLUSION

The statistically significant association between C-sections and ADHD in children can be partially explained by unmeasured confounding. Further research controlling for important confounders is required before firm conclusions can be drawn.

Evaluating chronic emotional dysregulation and irritability in relation to ADHD and depression genetic risk in children with ADHD

BACKGROUND

A central nosological problem concerns the etiological relationship of emotional dysregulation with ADHD. Molecular genetic risk scores provide a novel method for informing this question.

METHODS

Participants were 514 community-recruited children of Northern European descent age 7-11 defined as ADHD or non-ADHD by detailed research evaluation. Parents-rated ADHD on standardized ratings and child temperament on the Temperament in Middle Childhood Questionnaire (TMCQ) and reported on ADHD and comorbid disorders by semi-structured clinical interview. Categorical and dimensional variables were created for ADHD, emotional dysregulation (implicating disruption of regulation of both anger-irritability and of positive valence surgency-sensation seeking), and irritability alone (anger dysregulation). Genome-wide polygenic risk scores (PRS) were computed for ADHD and depression genetic liability. Structural equation models and computationally derived emotion profiles guided analysis.

RESULTS

The ADHD PRS was associated in variable-centered analyses with irritability (β = .179, 95% CI = 0.087-0.280; ΔR²  = .034, p < .0002), but also with surgency/sensation seeking (B = .146, 95%CI = 0.052-0.240, ΔR² =.022, p = .002). In person-centered analysis, the ADHD PRS was elevated in the emotion dysregulation ADHD group versus other ADHD children (OR = 1.44, 95% CI = 1.03-2.20, Nagelkerke ΔR²  = .013, p = .033) but did not differentiate irritable from surgent ADHD profiles. All effects were independent of variation in ADHD severity across traits or groups. The depression PRS was related to oppositional defiant disorder but not to ADHD emotion dysregulation.

CONCLUSIONS

Irritability-anger and surgency-sensation seeking, as forms of negative and positively valenced dysregulated affect in ADHD populations, both relate principally to ADHD genetic risk and not mood-related genetic risk.

Emotional lability and irritability have specific associations with symptomatology in children with attention deficit hyperactivity disorder

Irritability and emotional lability have been shown to be severity and impairment factors in community and clinical sample studies and are frequent comorbid features of Attention Deficit Hyperactivity Disorder (ADHD). However, while irritability and emotional lability seem to be closely linked, the differential effect of these two features has received little attention. This study assessed the distinct associations of irritability and emotional lability on symptomatology in children with ADHD. One hundred and eight children diagnosed with ADHD participated in the study. Children were rated by parents on ADHD and comorbid symptomatology with the Conners Rating Scale - Revised. Irritability was the most significant predictive factor of the severity of anxiety and oppositional symptoms. Regarding emotional lability, it was significantly predictive of the severity of hyperactivity symptoms. While emotional lability shares common theoretical characteristics with irritability, each seems to be associated with specific areas. Irritability is a symptom of Oppositional Defiant Disorder, a frequent ADHD comorbidity, and also seems to be related to internalizing disorder (e.g. anxiety). Emotional lability seems to be related to ADHD severity symptoms per se. Both could be clinically informative in the diagnosis of ADHD and its comorbidities.

The effects of emotional lability, mind wandering and sleep quality on ADHD symptom severity in adults with ADHD

Mind wandering, emotional lability and sleep quality are currently mostly independently investigated but are all interlinked and play a major role is adult attention-deficit/ hyperactivity disorder (ADHD). Emotional lability is a core feature of the disorder, excessive mind wandering has recently been linked to symptoms and impairments of ADHD and poor sleep quality is experienced by a clear majority of adults with ADHD. All three phenomena lead to functional impairment in ADHD, however their relationship to each other and to ADHD symptom severity is not well understood. Here we used serial multiple mediation models to examine the influence of mind wandering, sleep quality and emotional lability on ADHD symptom severity. 81 adults diagnosed with ADHD participated in this study. We found that mind wandering and emotional lability predicted ADHD symptom severity and that mind wandering, emotional lability and sleep quality were all linked and significantly contributed to the symptomatology of adult ADHD. Mind wandering was found to lead to emotional lability which in turn lead to ADHD symptom severity; and poor sleep quality was found to exacerbate mind wandering leading to ADHD symptoms. Future research should employ objective on-task measures of mind wandering, sleepiness and emotional lability to investigate the neural basis of these impairing deficits in ADHD.

Identifying Novel Types of Irritability Using a Developmental Genetic Approach

OBJECTIVE

Irritability, which is strongly associated with impairment and negative outcomes, is a common reason for referral to mental health services but is a nosological and treatment challenge. A major issue is how irritability should be conceptualized. The authors used a developmental approach to test the hypothesis that there are several forms of irritability, including a "neurodevelopmental/ADHD-like" type, with onset in childhood, and a "depression/mood" type, with onset in adolescence.

METHODS

Data were analyzed from the Avon Longitudinal Study of Parents and Children, a prospective U.K. population-based cohort. Irritability trajectory classes were estimated for 7,924 individuals with data at multiple time points across childhood and adolescence (four possible time points from approximately ages 7 to 15). Psychiatric diagnoses were assessed at approximately ages 7 and 15. Psychiatric genetic risk was indexed by polygenic risk scores (PRSs) for attention deficit hyperactivity disorder (ADHD) and depression, derived using large genome-wide association study results.

RESULTS

Five irritability trajectory classes were identified: low (81.2%), decreasing (5.6%), increasing (5.5%), late-childhood limited (5.2%), and high-persistent (2.4%). The early-onset high-persistent trajectory was associated with male preponderance, childhood ADHD (odds ratio=108.64, 95% CI=57.45-204.41), and ADHD PRS (odds ratio=1.31, 95% CI=1.09-1.58). The adolescent-onset increasing trajectory was associated with female preponderance, adolescent depression (odds ratio=5.14, 95% CI=2.47-10.73), and depression PRS (odds ratio=1.20, 95% CI=1.05-1.38). Both the early-onset high-persistent and adolescent-onset increasing trajectory classes were associated with adolescent depression diagnosis and ADHD PRS.

CONCLUSIONS

The developmental context of irritability may be important in its conceptualization: early-onset persistent irritability may be more neurodevelopmental/ADHD-like and later-onset irritability more depression/mood-like. These findings have implications for treatment as well as nosology.

Is Emotional Lability Distinct From "Angry/Irritable Mood," "Negative Affect," or Other Subdimensions of Oppositional Defiant Disorder in Children With ADHD?

OBJECTIVE

Emotional lability (EL) and oppositional defiant disorder (ODD) frequently co-occur with ADHD. This study evaluates whether EL merely represents the negative "mood/affect" component of ODD or forms a distinct dimension.

METHOD

EL and ODD data from 1,317 ADHD participants were analyzed using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) for binary data.

RESULTS

Within ADHD, 39.4% children had ODD and 42.6% had EL. A sizable proportion expressed only either ODD or EL: 16.6% had ODD-only, 19.7% had EL-only, and 22.9% expressed both. In both EFA and CFA, EL forms a separate dimension from ODD items and the "mood/affect" subdimensions (whether classified by Diagnostic and Statistical Manual of Mental Disorders [5th ed.; DSM-5] or the Burke et al. models or the de novo ODD subdimensions derived from our data). This factorial structure remains invariant across gender.

CONCLUSION

EL is distinct from ODD and its "mood/affect" subdimensions. In line with emerging evidence, our findings provide further evidence of factorial validity for EL as a separate construct from ODD.

Genome-wide analysis of emotional lability in adult attention deficit hyperactivity disorder (ADHD)

Emotional lability is strongly associated with Attention Deficit Hyperactivity Disorder (ADHD), represents a major source of impairment and predicts poor clinical outcome in ADHD. Given that no specific genes with a role in the co-occurrence of both conditions have been described, we conducted a GWAS of emotional lability in 563 adults with ADHD. Despite not reaching genome-wide significance, the results highlighted genes related with neurotransmission, cognitive function and a wide range of psychiatric disorders that have emotional lability as common clinical feature. By constructing polygenic risk scores on mood instability in the UK Biobank sample and assessing their association with emotional lability in our clinical dataset, we found suggestive evidence of common genetic variation contributing to emotional lability in general population and in clinically diagnosed ADHD. Although not conclusive, these tentative results are in agreement with previous studies that suggest emotion dysregulation as a transdiagnostic construct and highlight the need for further investigation to disentangle the genetic basis of mood instability in ADHD and co-occurring psychiatric disorders.

Valence, arousal or both? Shared emotional deficits associated with Attention Deficit and Hyperactivity Disorder and Oppositional/Defiant-Conduct Disorder symptoms in school-aged youth

We examined emotional responses in Attention Deficit Hyperactivity and Oppositional Defiant/Conduct Disorder to affective pictures. Eighty seven children (42 female, M_age = 11.2), with clinical or subclinical symptoms and controls viewed joy, fear, sadness or neutral pictures while heart rate, skin conductance, corrugator and zygomaticus responses were recorded. The moderating role of Callous-Unemotional and anxiety traits was evaluated. Lower resting heart rate and decreased skin conductance across picture types was associated with ADHD symptoms. Decreased heart rate reactivity to fear and sad stimuli was associated with ADHD and ODD/CD. Corrugator and zygomaticus responses were not associated with ADHD or ODD/CD. Findings are mostly consistent with a fearlessness account of disruptive behavior, and seem to also pertain to ADHD, with intact valence systems. Findings are discussed in light of the significance of identifying common pathogenic mechanisms across traditional diagnostic categories, consistent with trans-diagnostic approaches to the study of psychopathology.

Live fast, die young? A review on the developmental trajectories of ADHD across the lifespan

Attention-deficit/hyperactivity disorder (ADHD) is highly heritable and the most common neurodevelopmental disorder in childhood. In recent decades, it has been appreciated that in a substantial number of cases the disorder does not remit in puberty, but persists into adulthood. Both in childhood and adulthood, ADHD is characterised by substantial comorbidity including substance use, depression, anxiety, and accidents. However, course and symptoms of the disorder and the comorbidities may fluctuate and change over time, and even age of onset in childhood has recently been questioned. Available evidence to date is poor and largely inconsistent with regard to the predictors of persistence versus remittance. Likewise, the development of comorbid disorders cannot be foreseen early on, hampering preventive measures. These facts call for a lifespan perspective on ADHD from childhood to old age. In this selective review, we summarise current knowledge of the long-term course of ADHD, with an emphasis on clinical symptom and cognitive trajectories, treatment effects over the lifespan, and the development of comorbidities. Also, we summarise current knowledge and important unresolved issues on biological factors underlying different ADHD trajectories. We conclude that a severe lack of knowledge on lifespan aspects in ADHD still exists for nearly every aspect reviewed. We encourage large-scale research efforts to overcome those knowledge gaps through appropriately granular longitudinal studies.

The efficacy of Ritalin in ADHD children under neurofeedback training

Current research has shown that neurofeedback (NF) is a viable treatment for attention deficit hyperactivity disorder (ADHD), however having pharmacological approach alongside such stimulants is still inevitable. Therefore, the purpose of this study is the comparison of neurofeedback with Ritalin and without Ritalin in treating children with ADHD. This study was causal-comparative in design. Participants were children aged 5-10 years with ADHD; seven participants were in neurofeedback group with Ritalin and seven in neurofeedback without Ritalin group according to random split and parent's conformation. Clinical Q, Conner's continuous performance test (CPT), and WISC-R were used before and after treatment. For analyzing data, we used descriptive statistical and Mann Whitney U tests. Results showed that even if the two groups were modified in all components, modifications of commission and reaction time of the CPT and F4 theta/alpha of the clinical Q were more accurate in NF with Ritalin treatment rather than the other group. These findings suggest that neurofeedback is efficient in improving some of the behavioral concomitants of ADHD in children whose parents favored non-pharmacological treatment, but Ritalin and neurofeedback combination is more efficient. So, multimodal approach is strongly recommended for ADHD treatment.

The Difficulties in Emotion Regulation Scale-Parent Report: A Psychometric Investigation Examining Adolescents With and Without ADHD

Emotion dysregulation is associated with attention deficit/hyperactivity disorder (ADHD) and confers risk for behavior problems and functional impairment; however, there is little guidance on best practices for measurement in adolescents. We developed a parent-report version of the Difficulties in Emotion Regulation Scale (DERS-P). Evidence of reliability and validity was evaluated in a large community online sample (Study 1: n = 978; M_age = 13.52 years; SD = 1.93) and in two samples of adolescents with ADHD (Study 2, Sample 1: n = 78; M_age = 12.12 years, SD = 0.91; Sample 2: n = 206; M_age = 15.35 years; SD = 0.85). A four-factor solution of the DERS-P was obtained in Study 1 and confirmed in Study 2, with factors demonstrating acceptable internal consistency. The community sample was generally rated as less dysregulated than the ADHD samples. Support was obtained for convergent, concurrent, and incremental validity evidence. These findings provide preliminary evidence for the DERS-P as a psychometrically sound parent-report measure of emotion dysregulation in 11- to 17-year-old adolescents.

Practitioner Review: Definition, recognition, and treatment challenges of irritability in young people

BACKGROUND

Irritability is one of the most common reasons for referral to child and adolescent mental health services and is the main characteristic of the new diagnosis of disruptive mood dysregulation disorder (DMDD). However, the recognition and management of irritability presents a major challenge in clinical practice and may be partly responsible for the dramatic increase in antipsychotic prescribing in recent years.

METHODS

In this review, we provide up-to-date information on the definition and mechanisms underlying irritability, and its assessment in clinical practice. We aim to discuss the latest research on DMDD, and the presence of severe irritability in the context of other disorders, as well as to recommend a treatment algorithm.

RESULTS

Severe irritability is associated with aberrant reward processing and bias toward threatening stimuli. Several measures are available to easily assess irritability. The recent diagnosis of DMDD captures children whose main problem is severe irritability and differ from those with bipolar disorder in longitudinal outcomes, family history, and behavioral and neural correlates. Treatment of irritability might depend on the context it appears. Indirect evidence suggests that parent management training (PMT) and cognitive behavioral therapy (CBT) are the most supported psychological treatments for irritability.

CONCLUSIONS

Irritability, recognized as a mood problem rather than a purely behavioral manifestation, is a common condition for young people. Practitioners should not ignore irritability as it is associated with substantial morbidity and impairment. Although there are no trials with irritability as main outcome, clinicians can apply several existing pharmacological and psychological interventions for its treatment. Also, new promising approaches relying on pathophysiological findings, such as exposure-based cognitive behavioral therapy techniques and interpretation bias training (IBT), are being currently investigated.

Emotional Lability in Preschoolers With Symptoms of ADHD

OBJECTIVE

The aim of this study was to examine occurrence of emotional lability (EL) in preschoolers with ADHD symptoms versus controls.

METHOD

The study was part of the Norwegian Mother and Child Cohort Study (MoBa) at the Norwegian Institute of Public Health. In the present study, 495 preschoolers were clinically examined. Symptoms of ADHD, anxiety, and oppositional defiant disorder (ODD) were measured with the Preschool Age Psychiatric Assessment Interview. An EL measure was obtained from the Emotional Control subscale of the Behavior Rating Inventory of Executive Function-Preschool Version (BRIEF-P), which parents and teachers completed.

RESULTS

EL was significantly more frequent in the ADHD group compared with controls (25% vs. 7%, p < .001). By parent report, EL correlated significantly with ADHD-, anxiety-, and ODD symptoms. By teacher report, EL was significantly correlated only with hyperactivity-impulsivity.

CONCLUSION

EL appears identifiable in young preschoolers and was particularly associated with ODD in children with ADHD symptoms.

Convergence of BOLD and ERP measures of neural reactivity to emotional faces in children and adolescents with and without anxiety disorders

The neural bases of emotion are commonly measured using blood-oxygen-level-dependent (BOLD) signal and the late positive potential (LPP) event-related potential (ERP) component, but rarely together in the same individuals. Despite evidence of developmental changes in processing socio-emotional signals (e.g., faces) as reflected by both BOLD and LPP indices of brain maturation, the literature on the correspondence between these measures is limited to healthy adults, leaving questions regarding such correspondence across development and in clinical populations unaddressed. We examined the relationship between BOLD and LPP during an emotional face processing task in a large sample of youth (N = 70; age 7-19 years) with and without anxiety disorders, and tested whether BOLD signal in regions corresponding to LPP may account for age-related decreases in LPP. Greater activation in bilateral inferior frontal gyrus (IFG)/orbitofrontal gyrus (OFG), left supplementary motor area, right superior parietal lobule, and bilateral amygdala correlated with enhanced LPP to emotional faces in both anxious and healthy youth. Older youth exhibited reduced activation in bilateral IFG/OFG and bilateral amygdala, as well as reduced LPP. Decreased right IFG/OFG activation mediated the association between age and LPP. These findings support correspondence between these measures and need for multi-method approaches and indicate that age-related decreases in LPP may be driven, in part, by decreased IFG/OFG activation.

Gender associated developmental trajectories of SDQ-dysregulation profile and its predictors in children

BACKGROUND

Severe mood dysregulation is common in childhood and can be highly impairing. The Dysregulation Profile (DP) can be considered as a broader phenotype of emotional dysregulation, including affect, cognition and behaviour. Since mood dysregulation may persist, but differently in boys and girls, the gender associated course needs to be considered longitudinally to gain a better insight in order to support the children more adequately. This study is focusing on gender associated subgroup trajectories of the Strengths and Difficulties Questionnaire-Dysregulation Profile (SDQ-DP) in middle childhood (9-13 years of age) and includes the potential impact of clinical and psychosocial characteristics.

METHOD

The data set was available from the BELLA study on mental health and well-being in children and adolescents, which is the mental health module of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). A representative epidemiological sample of 564 children living in Germany was examined at three assessment points over 2 years (data collection 2003-2006). The SDQ-DP of children aged 9-13 years was evaluated using Latent Class Growth Analysis (LCGA).

RESULTS

For both genders three trajectories with low (girls 67.0% and boys 59.5%), moderate (girls 28.0% and boys 31.7%) and high SDQ-DP (girls 5.0% and boys 8.8%) scores were detected. The courses of low and moderate subgroups were stable, while in the high SDQ-DP subgroup boys showed a decreasing and girls an increasing trend in symptom severity on a descriptive level. The results of the multinomial logistic regression analyses revealed a significant influence of mainly externalising but also internalising problems both increasing the risk of moderate and high SDQ-DP in both genders. Good quality of life was a protective factor for the SDQ-DP course in all subgroups.

CONCLUSION

In addition to the known clinical and scientific value of the SDQ-DP, three distinguishable trajectories of SDQ-DP in boys and girls could be found. High externalising problems at the beginning of the trajectory were associated with an undesirable course of SDQ-DP. These findings might be helpful for better psychoeducation, counselling and monitoring in clinical cases and public health.

Antidepressant use during pregnancy and the risk of attention-deficit/hyperactivity disorder in the children: a meta-analysis of cohort studies

BACKGROUND

Evidence for the relationship between antidepressant use during pregnancy and the risk of attention-deficit/hyperactivity disorder (ADHD) in the children is conflicting.

OBJECTIVE

To assess the association between fetal exposure to antidepressant drugs and the subsequent development of ADHD.

SEARCH STRATEGY

A systematic literature search was conducted in PubMed, EMBASE, PsycINFO, and CINAHL databases to identify relevant cohort studies published from inception until October 2017.

SELECTION CRITERIA

Cohort studies, identifying children with ADHD diagnosis and linking antidepressant use during pregnancy in their mothers.

DATA COLLECTION

Two reviewers independently abstracted data and assessed study quality.

MAIN RESULTS

The literature search identified six relevant cohort studies with association between antidepressant exposure during pregnancy and the risk of ADHD in children [hazard ratio (HR) 1.34; 95% confidence interval (CI) 1.14-1.57]. However, the association was not statistically significant when the reference group was mothers with psychiatric disorders not treated during pregnancy (HR 0.96; 95% CI 0.76-1.2; n = 2 studies). Moreover, preconception exposure to antidepressants was significantly associated with increased risk of ADHD (HR 1.82; 95% CI 1.54-2.15; n = 3 studies).

CONCLUSIONS

The significant association between antidepressant exposure during pregnancy and ADHD in the children can be partially explained by confounding by indication. Given the low number of included studies, further studies with prospective designs that use validated measurements and controls for important confounders are needed to verify our findings.

TWEETABLE ABSTRACT

Antidepressant use during pregnancy may be not associated with ADHD in the offspring.

Examining the Etiology of Reading Disability as Conceptualized by the Hybrid Model

A fairly recent definition of reading disability (RD) is that in the form of a hybrid model. The model views RD as a latent construct that is manifested through various observable unexpected impairments in reading related skills and through inadequate response to intervention. The current report evaluated this new conceptualization of RD from an etiological perspective. The sample consisted of 2737 twin pairs in first through fourth grade (M_age = 8.52) from the Florida Twin Project on Reading. Using twin analyses, results showed that a substantial proportion of genetic variance, a small proportion of shared environmental, and a small proportion of non-shared environmental variance was attributed to the RD factor. Findings suggest that the etiological architecture of RD closely mirrors the structure of the hybrid model of RD.

Investigating the genetic underpinnings of early-life irritability

Severe irritability is one of the commonest reasons prompting referral to mental health services. It is frequently seen in neurodevelopmental disorders that manifest early in development, especially attention-deficit/hyperactivity disorder (ADHD). However, irritability can also be conceptualized as a mood problem because of its links with anxiety/depressive disorders; notably DSM-5 currently classifies severe, childhood-onset irritability as a mood disorder. Investigations into the genetic nature of irritability are lacking although twin studies suggest it shares genetic risks with both ADHD and depression. We investigated the genetic underpinnings of irritability using a molecular genetic approach, testing the hypothesis that early irritability (in childhood/adolescence) is associated with genetic risk for ADHD, as indexed by polygenic risk scores (PRS). As a secondary aim we investigated associations between irritability and PRS for major depressive disorder (MDD). Three UK samples were utilized: two longitudinal population-based cohorts with irritability data from childhood (7 years) to adolescence (15-16 years), and one ADHD patient sample (6-18 years). Irritability was defined using parent reports. PRS were derived from large genome-wide association meta-analyses. We observed associations between ADHD PRS and early irritability in our clinical ADHD sample and one of the population samples. This suggests that early irritability traits share genetic risk with ADHD in the general population and are a marker of higher genetic loading in individuals with an ADHD diagnosis. Associations with MDD PRS were not observed. This suggests that early-onset irritability could be conceptualized as a neurodevelopmental difficulty, behaving more like disorders such as ADHD than mood disorders.

Is emotional lability a marker for attention deficit hyperactivity disorder, anxiety and aggression symptoms in preschoolers?

BACKGROUND

Emotional lability (EL) is frequent in school-aged children with attention deficit hyperactivity disorder (ADHD) and is associated with more frequent comorbidities and more severe impairment. However, little research has investigated the association between EL, ADHD and comorbid symptoms in preschoolers. This study assessed dimensional EL in preschoolers and its link with ADHD symptoms (e.g. hyperactivity-impulsivity and inattention) and behavioural and emotional problems (e.g. aggression and anxiety).

METHOD

One hundred and fifty-four preschoolers aged 3-6 years old were rated on questionnaires by parents. EL was assessed with the index from the Conners Rating Scale-Revised and behavioural and emotional problems with an adapted version of the Social Behavior Questionnaire. Multiple linear regressions analyses were conducted.

RESULTS

Higher EL was associated with higher hyperactivity-impulsivity, inattention, anxiety and aggression problems. After controlling for other behavioural and emotional problems and sociodemographic variables, EL remained associated with hyperactivity-impulsivity and anxiety.

CONCLUSIONS

Emotional lability seems to be a potential marker for ADHD symptoms with internalizing problems in preschoolers and could be a target for diagnosis and early interventions. This finding should be treated with caution as the study was limited by the low response rate of the participants and consequently the small sample size.

Attenuated neural reactivity to happy faces is associated with rule breaking and social problems in anxious youth

Pediatric anxiety is associated with comorbid externalizing behaviors and social problems, and these associations may be related to altered emotion processing. The late positive potential (LPP), an event-related potential component, is a neural marker of emotion processing, and there is evidence that anxious youth exhibits enhanced LPPs to threatening signals. It is unknown, however, if differences in the LPP are related to externalizing behaviors and social problems co-occurring with anxiety and if these associations are driven by altered processing of threatening (angry or fearful faces) or rewarding (happy faces) socio-emotional signals. Thus, in the present study, we examined, in a sample of 39 anxious youth, the association between LPPs, following socio-emotional signals and externalizing behaviors and social problems. Results indicated an association between attenuated LPPs in response to happy faces and greater rule-breaking and social problems. These findings suggest that differences in positive socio-emotional signal processing are related to heterogeneity in pediatric anxiety and that LPPs are a sensitive index of such heterogeneity.

ADHD and Emotion Dysregulation Among Children and Adolescents

Individuals with attention-deficit/hyperactivity disorder (ADHD) experience impairments in a number of functional domains. Although current evidence-based treatments for ADHD reduce symptoms and improve academic and behavioral functioning, they have minimal impact on social functioning or on risky behaviors (see Evans et al. in J Clin Child Adolesc Psychol, 43:527-551, 2014 for review). Preliminary evidence indicates that emotion dysregulation (ED) is associated with impairments across the developmental spectrum, such as social impairment and risky behaviors, and that its relative absence/presence is differentially associated with treatment response. It thus stands to reason that by incorporating a focus on ED in interventions targeting social impairment and risky behaviors, we may be able to increase the number of youth who respond to such interventions and decrease the prevalence or degree of these impairments and behaviors among youth and adults with ADHD. However, a number of questions remain unaddressed about the association between ADHD and ED, such as the portion of individuals with ADHD who experience ED, the extent to which ED is associated with the above impairments and behaviors, and whether or not ED is malleable. To begin addressing these questions, we summarize and critically evaluate the literature on the association between ADHD and ED and make recommendations for future basic, translational, and treatment outcome research.

Heritability of Intraindividual Mean and Variability of Positive and Negative Affect

Positive affect (e.g., attentiveness) and negative affect (e.g., upset) fluctuate over time. We examined genetic influences on interindividual differences in the day-to-day variability of affect (i.e., ups and downs) and in average affect over the duration of a month. Once a day, 17-year-old twins in the United Kingdom (N = 447) rated their positive and negative affect online. The mean and standard deviation of each individual’s daily ratings across the month were used as the measures of that individual’s average affect and variability of affect. Analyses revealed that the average of negative affect was significantly heritable (.53), but the average of positive affect was not; instead, the latter showed significant shared environmental influences (.42). Fluctuations across the month were significantly heritable for both negative affect (.54) and positive affect (.34). The findings support the two-factor theory of affect, which posits that positive affect is more situational and negative affect is more dispositional.

Genetic and environmental influences on the relationship between ADHD symptoms and internalizing problems: A Chinese twin study

Several twin studies have investigated the overlap between attention deficit hyperactivity disorder (ADHD) and externalizing problems; however, limited information is known regarding the genetic and environmental contribution to the overlap between ADHD and internalizing problems. This study examined the genetic and environmental influences on the variation in and covariation between ADHD symptoms and internalizing problems by using the Child Behavior Checklist (CBCL). We investigated 1,316 child and adolescent twins, including 780 monozygotic twins and 536 dizygotic twins, aged 6 years to 18 years from the Chinese Child and Adolescent Twin Registry. ADHD symptoms and internalizing problems were quantified through parent rating by using the Attention Problems Scale and other three scales, which include Anxious/Depressed, Withdrawn, and Somatic Complaints of CBCL. Genetic and environmental susceptibilities common to ADHD symptoms and internalizing problems were examined through bivariate twin modeling. Results showed that genetic factors substantially influenced the ADHD symptoms with a heritability of 72%. Modest genetic influences and substantial shared environmental influences (20-77%) were observed in the three internalizing problem scales. Common genetic and shared environmental influences were essential for the overlap between ADHD and the three internalizing problems respectively. Approximately one-fifth of the genetic variance of ADHD symptoms was shared with anxiety/depression. In conclusion, substantial genetic and shared environmental influences on ADHD symptoms and internalizing problems were observed in Chinese children and adolescents. Our finding supports a common etiology between ADHD and internalizing problems. This finding can also help explain the co-existence of these behavior problems. © 2015 Wiley Periodicals, Inc.

Adult attention-deficit hyperactivity disorder: key conceptual issues

For many years, attention-deficit hyperactivity disorder (ADHD) was thought to be a childhood-onset disorder that has a limited effect on adult psychopathology. However, the symptoms and impairments that define ADHD often affect the adult population, with similar responses to drugs such as methylphenidate, dexamphetamine, and atomoxetine, and psychosocial interventions, to those seen in children and adolescents. As a result, awareness of ADHD in adults has rapidly increased and new clinical practice has emerged across the world. Despite this progress, treatment of adult ADHD in Europe and many other regions of the world is not yet common practice, and diagnostic services are often unavailable or restricted to a few specialist centres. This situation is remarkable given the strong evidence base for safe and effective treatments. Here we address some of the key conceptual issues surrounding the diagnosis of ADHD relevant to practising health-care professionals working with adult populations. We conclude that ADHD should be recognised in the same way as other common adult mental health disorders, and that failure to recognise and treat ADHD is detrimental to the wellbeing of many patients seeking help for common mental health problems.

Six-year follow-up study of combined type ADHD from childhood to young adulthood: Predictors of functional impairment and comorbid symptoms

BACKGROUND

ADHD in childhood is associated with development of negative psychosocial and behavioural outcomes in adults. Yet, relatively little is known about which childhood and adulthood factors are predictive of these outcomes and could be targets for effective interventions. To date follow-up studies have largely used clinical samples from the United States with children ascertained at baseline using broad criteria for ADHD including all clinical subtypes or the use of DSM III criteria.

AIMS

To identify child and adult predictors of comorbid and psychosocial comorbid outcomes in ADHD in a UK sample of children with DSM-IV combined type ADHD.

METHOD

One hundred and eighteen adolescents and young adults diagnosed with DSM-IV combined type ADHD in childhood were followed for an average of 6years. Comorbid mental health problems, drug and alcohol use and police contact were compared for those with persistent ADHD, sub-threshold ADHD and population norms taken from the Adult Psychiatric Morbidity Study 2007. Predictors included ADHD symptomology and gender.

RESULTS

Persistent ADHD was associated with greater levels of anger, fatigue, sleep problems and anxiety compared to sub-threshold ADHD. Comorbid mental health problems were predicted by current symptoms of hyperactivity-impulsivity, but not by childhood ADHD severity. Both persistent and sub-threshold ADHD was associated with higher levels of drug use and police contact compared to population norms.

CONCLUSIONS

Young adults with a childhood diagnosis of ADHD showed increased rates of comorbid mental health problems, which were predicted by current levels of ADHD symptoms. This suggests the importance of the continuing treatment of ADHD throughout the transitional years and into adulthood. Drug use and police contact were more common in ADHD but were not predicted by ADHD severity in this sample.

Development of graphomotor fluency in adults with ADHD: Evidence of attenuated procedural learning

PURPOSE

The present study sought to determine if adults with ADHD demonstrate reduced graphomotor learning relative to controls.

METHOD

Twenty-eight control adults (n=14) and adults with ADHD (n=14) were recruited and wrote a novel grapheme on a digitizing tablet 30 times. Participants with ADHD were counterbalanced on and off stimulant medication.

RESULTS

Control participants, F(1,13)=13.786, p=.003, ω(2)partial=.460, and participants with ADHD on medication, F(1,13)=10.462, p=.007, ω(2)partial=.387, demonstrated significant improvement in graphomotor fluency with equivalent practice whereas participants with ADHD off medication did not, F(1,12)=0.166, NS.

CONCLUSIONS

Results indicate that graphomotor program learning in adults with ADHD may occur more slowly than typically developing peers. Findings have implications for providing accommodations to adults with ADHD, potential benefits of stimulant medication, and using digitizing technology as a neuropsychological assessment instrument.

Attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a persistent neurodevelopmental disorder that affects 5% of children and adolescents and 2.5% of adults worldwide. Throughout an individual's lifetime, ADHD can increase the risk of other psychiatric disorders, educational and occupational failure, accidents, criminality, social disability and addictions. No single risk factor is necessary or sufficient to cause ADHD. In most cases ADHD arises from several genetic and environmental risk factors that each have a small individual effect and act together to increase susceptibility. The multifactorial causation of ADHD is consistent with the heterogeneity of the disorder, which is shown by its extensive psychiatric co-morbidity, its multiple domains of neurocognitive impairment and the wide range of structural and functional brain anomalies associated with it. The diagnosis of ADHD is reliable and valid when evaluated with standard criteria for psychiatric disorders. Rating scales and clinical interviews facilitate diagnosis and aid screening. The expression of symptoms varies as a function of patient developmental stage and social and academic contexts. Although there are no curative treatments for ADHD, evidenced-based treatments can markedly reduce its symptoms and associated impairments. For example, medications are efficacious and normally well tolerated, and various non-pharmacological approaches are also valuable. Ongoing clinical and neurobiological research holds the promise of advancing diagnostic and therapeutic approaches to ADHD. For an illustrated summary of this Primer, visit: http://go.nature.com/J6jiwl.

Types of adult attention-deficit hyperactivity disorder (ADHD): baseline characteristics, initial response, and long-term response to treatment with methylphenidate

Much recent research describes the importance of emotional symptoms in ADHD. While there is no accepted system for including emotionality in diagnosing ADHD, the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS) provides a tool to facilitate this. It assesses a range of adult ADHD symptoms which load on two factors: inattentive and emotional dysregulation. The consistently high inattentive factor was used to define significant elevation on the more variable emotional dysregulation factor (which contains four WRAADDS domains: hyperactivity/restlessness, temper, affective lability, and emotional over-reactivity) allowing the definition of two ADHD diagnostic types. We compared these two types on a broad range of adult subject characteristics, including response to methylphenidate (MPH) treatment assessed during two clinical trials. Marked impairment in three of the four emotional domains reflected a symptom severity level equivalent to that of the inattentive factor. 59 % met this threshold, defining them as ADHD emotion dysregulation presentation, as opposed to 41 % with ADHD inattentive presentation. Cluster analysis validated these groups by generating similar clusters with 85 % agreement regarding membership. ADHD emotional dysregulation presentation subjects showed more childhood ADHD symptoms, adult symptoms of oppositional defiant disorder, and evidence of personality disorder. Both types showed similar improvement during the double-blind MPH arm of the trials and during a 6-month open-label phase. Based on the presence of symptoms of emotional dysregulation, ADHD in adults can be conceptualized as two types. Impairment and comorbidity in adults with ADHD are largely concentrated in ADHD emotional dysregulation presentation patients.

Aberrant amygdala intrinsic functional connectivity distinguishes youths with bipolar disorder from those with severe mood dysregulation

It remains unclear the degree to which youths with episodic mania (bipolar disorder; BD) vs. those with chronic, severe irritability (severe mood dysregulation, SMD) should be placed in similar or distinct diagnostic groups. Addressing this clinically meaningful question requires greater understanding of the neural alterations underlying both disorders. We evaluated resting state functional magnetic resonance imaging data of 53 youths (14 BD, 20 healthy volunteers (HV), and 19 SMD, ages 9-18.5 years). Seed regions of interest were the bilateral basolateral, superficial and centromedial amygdala, defined using the Juelich probabilistic atlas. We found a significant between-group difference in functional connectivity between the left basolateral amygdala and the medial aspect of the left frontal pole plus the posterior cingulate/precuneus. This finding was driven by hyperconnectivity among BD vs. HV or SMD youths. As with earlier data, these findings suggest that the pathophysiology of BD and SMD may differ.