Commentary: Whither the epigenetics of child psychopathology? Some reflections provoked by Barker et al. (2018)

Barker et al.'s. () review addresses one of the most fundamental questions in the fields of child psychology and psychiatry - How can adverse experiences shape development to a sufficient degree and in profound and enduring ways to create long term risk for later mental disorder and disability? In particular they discuss the plausibility of differential methylation as an epigenetic mechanism by which such exposures can become neuro-biologically embedded. Our commentary rises six question relating to key issues that need to be addressed as we search for definitive evidence from human studies that such mechanisms actually do make an important causal contribution to abnormal trajectories of development to disorder.

The Moderating Effect of Self-Reported State and Trait Anxiety on the Late Positive Potential to Emotional Faces in 6-11-Year-Old Children

Introduction: The emergence of anxiety during childhood is accompanied by the development of attentional biases to threat. However, the neural mechanisms underlying these biases are poorly understood. In addition, previous research has not examined whether state and trait anxiety are independently associated with threat-related biases. Methods: We compared ERP waveforms during the processing of emotional faces in a population sample of 58 6-11-year-olds who completed self-reported measures of trait and state anxiety and depression. Results: The results showed that the P1 was larger to angry than neutral faces in the left hemisphere, though early components (P1, N170) were not strongly associated with child anxiety or depression. In contrast, Late Positive Potential (LPP) amplitudes to angry (vs. neutral) faces were significantly and positively associated with symptoms of anxiety/depression. In addition, the difference between LPPs for angry (vs. neutral) faces was independently associated with state and trait anxiety symptoms. Discussion: The results showed that neural responses to facial emotion in children with elevated symptoms of anxiety and depression were most evident at later processing stages characterized as evaluative and effortful. The findings support cognitive models of threat perception in anxiety and indicate that trait elements of anxiety and more transitory fluctuations in anxious affect are important in understanding individual variation in the neural response to threat in late childhood.

'The way we do the things we do' - decision making transparency at the Journal of Child Psychology and Psychiatry

As in life generally, so in scholarly publishing, the turn of the year inevitably encourages editors to reflect soberly and take honest stock of the progress their journals have made over the previous 12 months. In this frame of mind, my own thoughts turned to our beloved Journal of Child Psychology and Psychiatry. Of course I say ours because we who currently work at the journal, know it actually belongs to you, the world-wide community of child and adolescent psychologists and psychiatrists: We are only its stewards. We hold it in trust for the whole field. We understand the important role that it has served, in shaping the field of scientific child psychology and psychiatry. We know it has a special place in both your intellectual and working lives. We are aware how important it is to you that the journal continues, on your behalf, to help drive the promotion of science-driven and evidence-based solutions to the great, and, in some aspects, growing, burden of suffering imposed by childhood mental and neuro-developmental disorders. It is vital that we have your confidence that we do this in a transparent and fair way - without fear or favour - not letting our own preconceptions, prejudices or vested interests influence the content of what we publish - unless it is our prejudice towards, and vested interest in, finding out 'the truth of the matter'. We are acutely aware of the responsibility that all this places on our shoulders - a yoke we feel privileged to bear.

Sex differences in risk-based decision making in adolescents with conduct disorder

Altered decision making processes and excessive risk-seeking behaviours are key features of conduct disorder (CD). Previous studies have provided compelling evidence of abnormally increased preference for risky options, higher sensitivity to rewards, as well as blunted responsiveness to aversive outcomes in adolescents with CD. However, most studies published to date have focused on males only; thus, it is not known whether females with CD show similar alterations in decision making. The current study investigated potential sex differences in decision making and risk-seeking behaviours in adolescents with CD. Forty-nine adolescents with CD (23 females) and 51 control subjects (27 females), aged 11-18 years, performed a computerised task assessing decision making under risk-the Risky Choice Task. Participants made a series of decisions between two gamble options that varied in terms of their expected values and probability of gains and losses. This enabled the participants' risk preferences to be determined. Taking the sample as a whole, adolescents with CD exhibited increased risk-seeking behaviours compared to healthy controls. However, we found a trend towards a sex-by-group interaction, suggesting that these effects may vary by sex. Follow-up analyses showed that males with CD made significantly more risky choices than their typically developing counterparts, while females with CD did not differ from typically developing females in their risk-seeking behaviours. Our results provide preliminary evidence that sex may moderate the relationship between CD and alterations in risk attitudes and reward processing, indicating that there may be sex differences in the developmental pathways and neuropsychological deficits that lead to CD.

An electrophysiological investigation of reinforcement effects in attention deficit/hyperactivity disorder: Dissociating cue sensitivity from down-stream effects on target engagement and performance

Objective

Neural hypo-sensitivity to cues predicting positive reinforcement has been observed in ADHD using the Monetary Incentive Delay (MID) task. Here we report the first study using an electrophysiological analogue of this task to distinguish between (i) cue related anticipation of reinforcement and downstream effects on (ii) target engagement and (iii) performance in a clinical sample of adolescents with ADHD and controls.

Methods

Thirty-one controls and 32 adolescents with ADHD aged 10–16 years performed the electrophysiological (e)-MID task − in which preparatory cues signal whether a response to an upcoming target will be reinforced or not − under three conditions; positive reinforcement, negative reinforcement (response cost) and no consequence (neutral). We extracted values for both cue-related potentials known to be, both, associated with response preparation and modulated by reinforcement (Cue P3 and Cue CNV) and target-related potentials (target P3) and compared these between ADHD and controls.

Results

ADHD and controls did not differ on cue-related components on neutral trials. Against expectation, adolescents with ADHD displayed Cue P3 and Cue CNV reinforcement-related enhancement (versus neutral trials) compared to controls. ADHD individuals displayed smaller target P3 amplitudes and slower and more variable performance − but effects were not modulated by reinforcement contingencies. When age, IQ and conduct problems were controlled effects were marginally significant but the pattern of results did not change.

Discussion

ADHD was associated with hypersensitivity to positive (and marginally negative) reinforcement reflected on components often thought to be associated with response preparation − however these did not translate into improved attention to targets. In the case of ADHD, upregulated CNV may be a specific marker of hyper-arousal rather than an enhancement of anticipatory attention to upcoming targets. Future studies should examine the effects of age, IQ and conduct problems on reinforcement sensitivity in ADHD.

Sex Differences in the Relationship Between Conduct Disorder and Cortical Structure in Adolescents

OBJECTIVE

Previous studies have reported reduced cortical thickness and surface area and altered gyrification in frontal and temporal regions in adolescents with conduct disorder (CD). Although there is evidence that the clinical phenotype of CD differs between males and females, no studies have examined whether such sex differences extend to cortical and subcortical structure.

METHOD

As part of a European multisite study (FemNAT-CD), structural magnetic resonance imaging (MRI) data were collected from 48 female and 48 male participants with CD and from 104 sex-, age-, and pubertal-status-matched controls (14-18 years of age). Data were analyzed using surface-based morphometry, testing for effects of sex, diagnosis, and sex-by-diagnosis interactions, while controlling for age, IQ, scan site, and total gray matter volume.

RESULTS

CD was associated with cortical thinning and higher gyrification in ventromedial prefrontal cortex in both sexes. Males with CD showed lower, and females with CD showed higher, supramarginal gyrus cortical thickness compared with controls. Relative to controls, males with CD showed higher gyrification and surface area in superior frontal gyrus, whereas the opposite pattern was seen in females. There were no effects of diagnosis or sex-by-diagnosis interactions on subcortical volumes. Results are discussed with regard to attention-deficit/hyperactivity disorder, depression, and substance abuse comorbidity, medication use, handedness, and CD age of onset.

CONCLUSION

We found both similarities and differences between males and females in CD-cortical structure associations. This initial evidence that the pathophysiological basis of CD may be partly sex-specific highlights the need to consider sex in future neuroimaging studies and suggests that males and females may require different treatments.

Child-to-adult neurodevelopmental and mental health trajectories after early life deprivation: the young adult follow-up of the longitudinal English and Romanian Adoptees study

BACKGROUND

Time-limited, early-life exposures to institutional deprivation are associated with disorders in childhood, but it is unknown whether effects persist into adulthood. We used data from the English and Romanian Adoptees study to assess whether deprivation-associated adverse neurodevelopmental and mental health outcomes persist into young adulthood.

METHODS

The English and Romanian Adoptees study is a longitudinal, natural experiment investigation into the long-term outcomes of individuals who spent from soon after birth to up to 43 months in severe deprivation in Romanian institutions before being adopted into the UK. We used developmentally appropriate standard questionnaires, interviews completed by parents and adoptees, and direct measures of IQ to measure symptoms of autism spectrum disorder, inattention and overactivity, disinhibited social engagement, conduct or emotional problems, and cognitive impairment (IQ score <80) during childhood (ages 6, 11, and 15 years) and in young adulthood (22-25 years). For analysis, Romanian adoptees were split into those who spent less than 6 months in an institution and those who spent more than 6 months in an institution. We used a comparison group of UK adoptees who did not experience deprivation. We used mixed-effects regression models for ordered-categorical outcome variables to compare symptom levels and trends between groups.

FINDINGS

Romanian adoptees who experienced less than 6 months in an institution (n=67 at ages 6 years; n=50 at young adulthood) and UK controls (n=52 at age 6 years; n=39 at young adulthood) had similarly low levels of symptoms across most ages and outcomes. By contrast, Romanian adoptees exposed to more than 6 months in an institution (n=98 at ages 6 years; n=72 at young adulthood) had persistently higher rates than UK controls of symptoms of autism spectrum disorder, disinhibited social engagement, and inattention and overactivity through to young adulthood (pooled p<0·0001 for all). Cognitive impairment in the group who spent more than 6 months in an institution remitted from markedly higher rates at ages 6 years (p=0·0001) and 11 years (p=0·0016) compared with UK controls, to normal rates at young adulthood (p=0·76). By contrast, self-rated emotional symptoms showed a late-onset pattern with minimal differences versus UK controls at ages 11 years (p=0·0449) and 15 years (p=0·17), and then marked increases by young adulthood (p=0·0005), with similar effects seen for parent ratings. The high deprivation group also had a higher proportion of people with low educational achievement (p=0·0195), unemployment (p=0·0124), and mental health service use (p=0·0120, p=0·0032, and p=0·0003 for use when aged <11 years, 11-14 years, and 15-23 years, respectively) than the UK control group. A fifth (n=15) of individuals who spent more than 6 months in an institution were problem-free at all assessments.

INTERPRETATION

Notwithstanding the resilience shown by some adoptees and the adult remission of cognitive impairment, extended early deprivation was associated with long-term deleterious effects on wellbeing that seem insusceptible to years of nurturance and support in adoptive families.

FUNDING

Economic and Social Research Council, Medical Research Council, Department of Health, Jacobs Foundation, Nuffield Foundation.

Commentary: Extraordinary environments, extreme neuroplasticity and mental disorder - reflections on pathways from adversity to mental disorder prompted by McCrory, Gerin, and Viding (2017)

Neuroplasticity, the brain's capacity to be shaped in response to environmental experience, has been claimed to resemble a double-edged sword - potentiating growth and healing when individuals are exposed to normative, benign or therapeutic environments on the one hand, mediating mental disorder development in those exposed to adversity, on the other. However, questions about the scope and limits of neuroplasticity and, especially, its clinical significance, remain unanswered.

Structure and clinical correlates of obsessive-compulsive symptoms in a large sample of children and adolescents: a factor analytic study across five nations

The underlying structure of obsessive-compulsive disorder (OCD) remains to be confirmed in child and adolescent populations. In this paper we report the first factor analytic study of individual OCD items from Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS). OCD symptoms were assessed using the CY-BOCS symptom checklist in a sample of 854 patients with OCD (7-18 years of age) recruited from clinics in five countries. Pooled data were subjected to exploratory and confirmatory factor analysis (CFA) to identify the optimal factor structure. Various models were tested for age and gender subgroups. Also, the invariance of the solution across age and gender was tested and associations with demographic and clinical factors were explored. A three-factor model provided the best-fit solution. It consisted of the following factors: (1) harm/sexual, (2) symmetry/hoarding, (3) contamination/cleaning. The factor structure was invariant for age and gender across subgroups. Factor one was significantly correlated with anxiety, and factor two with depression and anxiety. Factor three was negatively correlated with tic disorder and attention-deficit/hyperactivity disorder (ADHD). Females had higher scores on factor two than males. The OCD symptom structure in children and adolescents is consistent across age and gender and similar to results from recent child and adolescents although hoarding may not be a separate factor. Our three-factor structure is almost identical to that seen in early studies on adults. Common mental disorders had specific patterns of associations with the different factors.

Preschool hyperactivity specifically elevates long-term mental health risks more strongly in males than females: a prospective longitudinal study through to young adulthood

Evidence of continuities between preschool hyperactivity and adult mental health problems highlights the potential value of targeting early identification and intervention strategies. However, specific risk factors are currently unclear. This large-scale prospective longitudinal study aimed to identify which hyperactive preschoolers are at the greatest long-term risk of poor mental health. One hundred and seventy children (89 females) rated as hyperactive by their parents, and 88 non-hyperactive controls (48 females) were identified from a community sample of 4215 3-year-olds. Baseline data relating to behavioral/emotional problems and background characteristics were collected. Follow-up mental health and functional impairment outcomes were collected between 14 and 25 years of age. At age 3 years, males and females in the hyperactive group had similarly raised levels of hyperactivity and other behavior problems. In adolescence/young adulthood, these individuals showed elevated symptoms of ADHD, conduct disorder, mood disorder, anxiety and autism, as well as functional impairment. Preschool hyperactivity was strongly predictive of poor adolescent/adult outcomes for males across domains with effects being specifically driven by hyperactivity. For females, the effects of preschool hyperactivity were smaller and dropped to non-significant levels when other preschool problems were taken into account. Environmental risk factors also differed between the sexes, although these may also have been mediated by genetic risk. In conclusion, these results demonstrate marked sex differences in preschool predictors of later adolescent/adult mental health problems. Future research should include a measure of preschool inattention as well as hyperactivity. The findings highlight the potential value of tailored approaches to early identification strategies.

Attention training for infants at familial risk of ADHD (INTERSTAARS): study protocol for a randomised controlled trial

Background

Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder that can negatively impact on an individual’s quality of life. It is pathophysiologically complex and heterogeneous with different neuropsychological processes being impaired in different individuals. Executive function deficits, including those affecting attention, working memory and inhibitory control, are common. Cognitive training has been promoted as a treatment option, based on the notion that by strengthening the neurocognitive networks underlying these executive processes, ADHD symptoms will also be reduced. However, if implemented in childhood or later, when the full disorder has become well-established, cognitive training has only limited value. INTERSTAARS is a trial designed to test a novel approach to intervention, in which cognitive training is implemented early in development, before the emergence of the disorder. The aim of INTERSTAARS is to train early executive skills, thereby increasing resilience and reducing later ADHD symptoms and associated impairment.

Methods/design

Fifty 10–14-month-old infants at familial risk of ADHD will participate in INTERSTAARS. Infants will be randomised to an intervention or a control group. The intervention aims to train early attention skills by using novel eye-tracking technology and gaze-contingent training paradigms. Infants view animated games on a screen and different events take place contingent on where on the screen the infant is looking. Infants allocated to the intervention will receive nine weekly home-based attention training sessions. Control group infants will also receive nine weekly home visits, but instead of viewing the training games during these visits they will view non-gaze-contingent age-appropriate videos. At baseline and post treatment, infant attention control will be assessed using a range of eye-tracking, observational, parent-report and neurophysiological measures. The primary outcome will be a composite of eye-tracking tasks used to assess infant attention skills. Follow-up data will be collected on emerging ADHD symptoms when the infants are 2 and 3 years old.

Discussion

This is the first randomised controlled trial to assess the potential efficacy of cognitive training as a prevention measure for infants at familial risk of ADHD. If successful, INTERSTAARS could offer a promising new approach for developing early interventions for ADHD.

Trial registration

International Standard Randomised Controlled Trial registry: ISRCTN37683928. Registered on 22 June 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1727-0) contains supplementary material, which is available to authorized users.

ADHD-associated risk taking is linked to exaggerated views of the benefits of positive outcomes

Attention deficit and hyperactivity disorder (ADHD) is often assumed to be associated with increased engagement in risk-taking behaviors. The current study sought to understand the mental processes underlying this association using a theory-driven behavioral economics perspective. Psychological risk-return models suggest that risk and benefit are inherently subjective, and risk taking is best understood as the interplay between cognitions and motivations regarding the benefits and risks of alternatives. A sample of 244 adults was assessed for ADHD symptoms. The likelihood of engagement in a range of risky behaviors (e.g., driving without wearing a seat belt), the magnitude of perceived benefit and risk ascribed to these behaviors, and benefit and risk attitudes of each participant were extracted from the Domain Specific Risk Taking (DOSPERT) scales. ADHD symptoms were correlated with more risky behaviors and perception of greater benefits from engaging in these behaviors, but were not correlated with risk perception. Mediation analysis revealed that the association between ADHD symptoms and engagement in risk taking was mediated by perceived benefits. These findings highlight the idea that people with high level ADHD symptoms tend to engage in risky behaviors because they find such behavior particularly appealing, rather than because they seek risk per se.

Editorial: The effects of early trauma and deprivation on human development - from measuring cumulative risk to characterizing specific mechanisms

Science is not a linear process of accumulating knowledge. To the contrary, progress in understanding is most likely to occur, especially in less 'mature' disciplines, when healthy debate between opposing points of view create a dialectic in which thesis and antithesis force a new synthesis. In developmental psychopathology, such tension between opposing schools of thought continue to play a vital role in driving discovery across a wide range of topics.

Does comorbid anxiety counteract emotion recognition deficits in conduct disorder?

BACKGROUND

Previous research has reported altered emotion recognition in both conduct disorder (CD) and anxiety disorders (ADs) - but these effects appear to be of different kinds. Adolescents with CD often show a generalised pattern of deficits, while those with ADs show hypersensitivity to specific negative emotions. Although these conditions often cooccur, little is known regarding emotion recognition performance in comorbid CD+ADs. Here, we test the hypothesis that in the comorbid case, anxiety-related emotion hypersensitivity counteracts the emotion recognition deficits typically observed in CD.

METHOD

We compared facial emotion recognition across four groups of adolescents aged 12-18 years: those with CD alone (n = 28), ADs alone (n = 23), cooccurring CD+ADs (n = 20) and typically developing controls (n = 28). The emotion recognition task we used systematically manipulated the emotional intensity of facial expressions as well as fixation location (eye, nose or mouth region).

RESULTS

Conduct disorder was associated with a generalised impairment in emotion recognition; however, this may have been modulated by group differences in IQ. AD was associated with increased sensitivity to low-intensity happiness, disgust and sadness. In general, the comorbid CD+ADs group performed similarly to typically developing controls.

CONCLUSIONS

Although CD alone was associated with emotion recognition impairments, ADs and comorbid CD+ADs were associated with normal or enhanced emotion recognition performance. The presence of comorbid ADs appeared to counteract the effects of CD, suggesting a potentially protective role, although future research should examine the contribution of IQ and gender to these effects.

Severe psychosocial deprivation in early childhood is associated with increased DNA methylation across a region spanning the transcription start site of CYP2E1

Exposure to adverse rearing environments including institutional deprivation and severe childhood abuse is associated with an increased risk for mental and physical health problems across the lifespan. Although the mechanisms mediating these effects are not known, recent work in rodent models suggests that epigenetic processes may be involved. We studied the impact of severe early-life adversity on epigenetic variation in a sample of adolescents adopted from the severely depriving orphanages of the Romanian communist era in the 1980s. We quantified buccal cell DNA methylation at ~400 000 sites across the genome in Romanian adoptees exposed to either extended (6-43 months; n=16) or limited duration (<6 months; n=17) of severe early-life deprivation, in addition to a matched sample of UK adoptees (n=16) not exposed to severe deprivation. Although no probe-wise differences remained significant after controlling for the number of probes tested, we identified an exposure-associated differentially methylated region (DMR) spanning nine sequential CpG sites in the promoter-regulatory region of the cytochrome P450 2E1 gene (CYP2E1) on chromosome 10 (corrected P=2.98 × 10(-5)). Elevated DNA methylation across this region was also associated with deprivation-related clinical markers of impaired social cognition. Our data suggest that environmental insults of sufficient biological impact during early development are associated with long-lasting epigenetic changes, potentially reflecting a biological mechanism linking the effects of early-life adversity to cognitive and neurobiological phenotypes.

Neurofeedback for Attention-Deficit/Hyperactivity Disorder: Meta-Analysis of Clinical and Neuropsychological Outcomes From Randomized Controlled Trials

OBJECTIVE

We performed meta-analyses of randomized controlled trials to examine the effects of neurofeedback on attention-deficit/hyperactivity disorder (ADHD) symptoms and neuropsychological deficits in children and adolescents with ADHD.

METHOD

We searched PubMed, Ovid, Web of Science, ERIC, and CINAHAL through August 30, 2015. Random-effects models were employed. Studies were evaluated with the Cochrane Risk of Bias tool.

RESULTS

We included 13 trials (520 participants with ADHD). Significant effects were found on ADHD symptoms rated by assessors most proximal to the treatment setting, that is, the least blinded outcome measure (standardized mean difference [SMD]: ADHD total symptoms = 0.35, 95% CI = 0.11-0.59; inattention = 0.36, 95% CI = 0.09-0.63; hyperactivity/impulsivity = 0.26, 95% CI = 0.08-0.43). Effects were not significant when probably blinded ratings were the outcome or in trials with active/sham controls. Results were similar when only frequency band training trials, the most common neurofeedback approach, were analyzed separately. Effects on laboratory measures of inhibition (SMD = 0.30, 95% CI = -0.10 to 0.70) and attention (SMD = 0.13, 95% CI = -0.09 to 0.36) were not significant. Only 4 studies directly assessed whether learning occurred after neurofeedback training. The risk of bias was unclear for many Cochrane Risk of Bias domains in most studies.

CONCLUSION

Evidence from well-controlled trials with probably blinded outcomes currently fails to support neurofeedback as an effective treatment for ADHD. Future efforts should focus on implementing standard neurofeedback protocols, ensuring learning, and optimizing clinically relevant transfer.

Investigating the Familial Basis of Heightened Risk-Taking in Adolescents With Conduct Disorder and Their Unaffected Relatives

Previous studies have demonstrated increased risk-taking in adolescents with Conduct Disorder (CD) compared with typically developing controls. Increased risk-taking may partly mediate the pathway from genetic or environmental risk to CD. We investigated the familial basis of risk-taking by examining whether the unaffected relatives of CD probands (n = 22) showed heightened risk-taking in a gambling task, in common with affected probands (n = 44). Adolescents with CD were more likely to select risky options than the typically developing controls (n = 37) and unaffected relatives. Our findings confirm the association between CD and increased risk-taking, but suggest that this decision-making style may not have a familial basis.

Annual Research Review: Transdiagnostic neuroscience of child and adolescent mental disorders--differentiating decision making in attention-deficit/hyperactivity disorder, conduct disorder, depression, and anxiety

BACKGROUND

Ineffective decision making is a major source of everyday functional impairment and reduced quality of life for young people with mental disorders. However, very little is known about what distinguishes decision making by individuals with different disorders or the neuropsychological processes or brain systems underlying these. This is the focus of the current review.

SCOPE AND METHODOLOGY

We first propose a neuroeconomic model of the decision-making process with separate stages for the prechoice evaluation of expected utility of future options; choice execution and postchoice management; the appraisal of outcome against expectation; and the updating of value estimates to guide future decisions. According to the proposed model, decision making is mediated by neuropsychological processes operating within three domains: (a) self-referential processes involved in autobiographical reflection on past, and prospection about future, experiences; (b) executive functions, such as working memory, inhibition, and planning, that regulate the implementation of decisions; and (c) processes involved in value estimation and outcome appraisal and learning. These processes are underpinned by the interplay of multiple brain networks, especially medial and lateralized cortical components of the default mode network, dorsal corticostriatal circuits underpinning higher order cognitive and behavioral control, and ventral frontostriatal circuits, connecting to brain regions implicated in emotion processing, that control valuation and learning processes.

FINDINGS AND CONCLUSION

Based on clinical insights and considering each of the decision-making stages in turn, we outline disorder-specific hypotheses about impaired decision making in four childhood disorders: attention-deficit/hyperactivity disorder (ADHD), conduct disorder (CD), depression, and anxiety. We hypothesize that decision making in ADHD is deficient (i.e. inefficient, insufficiently reflective, and inconsistent) and impulsive (biased toward immediate over delayed alternatives). In CD, it is reckless and insensitive to negative consequences. In depression, it is disengaged, perseverative, and pessimistic, while in anxiety, it is hesitant, risk-averse, and self-deprecating. A survey of current empirical indications related to these disorder-specific hypotheses highlights the limited and fragmentary nature of the evidence base and illustrates the need for a major research initiative in decision making in childhood disorders. The final section highlights a number of important additional general themes that need to be considered in future research.

The impact of ADHD on the health and well-being of ADHD children and their siblings

Childhood attention-deficit/hyperactivity disorder (ADHD) has been associated with reduced health and well-being of patients and their families. The authors undertook a large UK survey-based observational study of the burden associated with childhood ADHD. The impact of ADHD on both the patient (N = 476) and their siblings (N = 337) on health-related quality of life (HRQoL) and happiness was quantified using multiple standard measures [e.g. child health utility-9D (CHU-9D), EuroQol-5D-Youth]. In the analysis, careful statistical adjustments were made to ensure a like-for-like comparison of ADHD families with two different control groups. We controlled for carers' ADHD symptoms, their employment and relationship status and siblings' ADHD symptoms. ADHD was associated with a significant deficit in the patient's HRQoL (with a CHU-9D score of around 6 % lower). Children with ADHD also have less sleep and were less happy with their family and their lives overall. No consistent decrement to the HRQoL of the siblings was identified across the models, except that related to their own conduct problems. The siblings do, however, report lower happiness with life overall and with their family, even when controlling for the siblings own ADHD symptoms. We also find evidence of elevated bullying between siblings in families with a child with ADHD. Overall, the current results suggest that the reduction in quality of life caused by ADHD is experienced both by the child with ADHD and their siblings.

Editorial: Distinguishing between the challenges posed by surface and deep forms of heterogeneity to diagnostic systems: do we need a new approach to subtyping of child and adolescent psychiatric disorders

Diagnostic formulations attempt to impose order on the messy reality of psychopathological phenomena. By doing this, so their advocates argue, they provide both the platform necessary for systematic scientific study, and, crucially, the bridge of shared terms and concepts vital if psychiatric science is to be truly translational; where scientific endeavour is guided by clinical priorities and, in-turn, scientific findings innovate clinical practice. The diagnostic schemes we currently work with, taking DSM-5 as the obvious case, are the product of an interesting historical process of ongoing revision - at the same time pragmatic and scientific. On the one hand, it is a process both anchored firmly in historical precedent and constrained by the practical needs of clinicians, patients and health insurance companies. On the other hand, it is a process open to new empirical data about how to best cluster symptomatic expressions and differentiate clinical presentations - so that over historical time diagnostic categories achieve an increasingly accurate mapping of the taxonomy (i.e., underlying structure), and related pathophysiology, of psychiatric phenomenon. Resolving the inevitable tensions that arise when trying to reconcile these pragmatic (economic and professional) and scientific priorities has proved to be both challenging and contentious. The study of heterogeneity as exemplified by the articles highlighted in this editorial indicate a range of different approaches that can be effectively used to refine psychiatric taxonomies by incorporating developmental and pathophysiological data to help identify new putative subtypes of potential therapeutic significance.

"Turning down the heat": Is poor performance of children with ADHD on tasks tapping "hot" emotional regulation caused by deficits in "cool" executive functions?

Emotional dysregulation in daily life is very common in children with attention deficit hyperactivity disorder (ADHD). It is however not clear whether this reflects a specific deficit or that it may be the result of generic executive function (EF) deficits. The current study addresses this question by means of an emotional working memory (WM) task with 2 memory load conditions and four possible backgrounds (blank screen, neutral, positive or negative picture), which was administered to 38 typically developing children and 29 children with ADHD. Children responded slower on trials when negative pictures were presented at the background versus when neutral pictures were presented, indicating an emotional interference effect; however crucially, groups did not differ in this respect. Reaction times were also slower on trials with a neutral picture as background versus trials without a picture, with children with ADHD showing an enhanced interference effect. There was a main effect of WM load on performance, but it did not interact with interference or group effects. To summarize, the findings indicate a generic interference control deficit in the children with ADHD in the current sample, while they could not provide support for an emotional interference deficit.

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.