For the most part the science of neuro‐developmental conditions, such as autism and ADHD, is conducted within a framework defined by a paradigm that
assumes that these expressions of ...neuro‐developmental variation are disorders resulting from brain dysfunction.
the translational goal being to identify, then target, the source of such dysfunction to reduce disorder and resolve impairment. By shifting this perspective to one that defines such conditions as
divergence in thought and action underpinned by brain atypicality
, the neurodiversity paradigm offers a fresh scientific vision shaped by a new translational imperative. It shifts the focus of enquiry to understanding the way environments shape experience to either stifle or promote the well‐being and development of neurodivergent people. It also encourages the fullest possible participation of neurodivergent people in the scientific process. Together these two elements provide a platform for a new translational science of neurodevelopment.
The currently dominant neuro-cognitive model of Attention Deficit Hyperactivity Disorder (AD/HD) presents the condition as executive dysfunction (EDF) underpinned by disturbances in the fronto-dorsal ...striatal circuit and associated dopaminergic branches (e.g. meso-cortical). In contrast, motivationally-based accounts focus on altered reward processes and implicate fronto-ventral striatal reward circuits and those meso-limbic branches that terminate in the ventral striatum especially the nucleus accumbens. One such account, delay aversion (DEL), presents AD/HD as a motivational style—characterised by attempts to escape or avoid delay—arising from fundamental disturbances in these reward centres. While traditionally regarded as competing, EDF and DEL models have recently been presented as complimentary accounts of two psycho-patho-physiological subtypes of AD/HD with different developmental pathways, underpinned by different cortico-striatal circuits and modulated by different branches of the dopamine system. In the current paper we describe the development of this model in more detail. We elaborate on the neuro-circuitry possibly underpinning these two pathways and explore their developmental significance within a neuro-ecological framework.
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.
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.
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.
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.
Since the beginning of the COVID‐19 pandemic in early 2020, many governments have implemented national or regional lockdowns to slow the spread of infection. The widely anticipated negative impact ...these interventions would have on families, including on their mental health, were not included in decision models. The purpose of this editorial is, therefore, to stimulate debate by considering some of the barriers that have stopped governments setting the benefits of lockdown against, in particular, mental health costs during this process and so to make possible a more balanced approach going forward. First, evidence that lockdown causes mental health problems needs to be stronger. Natural experimental studies will play an essential role in providing such evidence. Second, innovative health economic approaches that allow the costs and benefits of lockdown to be compared directly are required. Third, we need to develop public health information strategies that allow more nuanced and complex messages that balance lockdown’s costs and benefits to be communicated. These steps should be accompanied by a major public consultation/engagement campaign aimed at strengthening the publics’ understanding of science and exploring beliefs about how to strike the appropriate balance between costs and benefits in public health intervention decisions.
Until recently, causal models of attention-deficit/hyperactivity disorder (ADHD) have tended to focus on the role of common, simple, core deficits. One such model highlights the role of executive ...dysfunction due to deficient inhibitory control resulting from disturbances in the frontodorsal striatal circuit and associated mesocortical dopaminergic branches. An alternative model presents ADHD as resulting from impaired signaling of delayed rewards arising from disturbances in motivational processes, involving frontoventral striatal reward circuits and mesolimbic branches terminating in the ventral striatum, particularly the nucleus accumbens. In the present article, these models are elaborated in two ways. First, they are each placed within their developmental context by consideration of the role of person × environment correlation and interaction and individual adaptation to developmental constraint. Second, their relationship to one another is reviewed in the light of recent data suggesting that delay aversion and executive functions might each make distinctive contributions to the development of the disorder. This provides an impetus for theoretical models built around the idea of multiple neurodevelopmental pathways. The possibility of neuropathologic heterogeneity in ADHD is likely to have important implications for the clinical management of the condition, potentially impacting on both diagnostic strategies and treatment options.
Background
Using data from the English & Romanian Adoptees (ERA) study, we recently reported that early time‐limited exposure to severe institutional deprivation is associated with early‐onset and ...persistent neurodevelopmental problems and later‐onset emotional problems. Here, we examine possible reasons for the late emergence of emotional problems in this cohort. Our main focus is on testing a developmental cascade mediated via the functional impact of early‐appearing neurodevelopmental problems on late adolescent functioning. We also explore a second putative pathway via sensitization to stress.
Methods
The ERA study includes 165 Romanian individuals who spent their early lives in grossly depriving institutions and were subsequently adopted into UK families, along with 52 UK adoptees with no history of deprivation. Age six years symptoms of neurodevelopmental problems and age 15 anxiety/depression symptoms were assessed via parental reports. Young adult symptoms of depression and anxiety were assessed by both parent and self‐reports; young adults also completed measures of stress reactivity, exposure to adverse life events, and functioning in work and interpersonal relationships.
Results
The path between early institutional deprivation and adult emotional problems was mediated via the impact of early neurodevelopmental problems on unemployment and poor friendship functioning during the transition to adulthood. The findings with regard to early deprivation, later life stress reactivity, and emotional problems were inconclusive.
Conclusions
Our analysis suggests that the risk for adult depression and anxiety following extreme institutional deprivation is explained through the effects of early neurodevelopmental problems on later social and vocational functioning. Future research should more fully examine the role of stress susceptibility in this model.
How is practical progress possible in child psychology and psychiatry? How does science advance to promote therapeutic innovation? The importance of the exciting stuff – new insights and ideas, ...studied using cutting edge and innovative technologies – is self‐evident. However, the philosophy of science has shown us that less obvious and more mundane elements are also essential. This is because scientific progress is only possible where attempts to break new ground are solidly anchored in a stable shared framework of assumptions – a metatheory – about the general nature of the phenomenon being studied. This framework defines what questions are considered ‘scientific’ – questions that it ‘makes sense’ to ask from a scientific point of view and those that are considered out of bounds (scientists with less subtle minds even considering such to be nonquestions rather than different sorts of questions). Kuhn called this framework a paradigm and the research activity that originates from it, normal science (Kuhn, 1962, The Structure of Scientific Revolutions; Princeton, NJ: Princeton University Press). These frameworks also serve a vital regulatory function because they contain common concepts that embody shared points of reference that allow scientists to communicate with each other to share their ideas, hypotheses and findings (Habermas, 1979, Communication and the evolution of society; Boston: Beacon Press).
Background
A diagnosis of attention‐deficit/hyperactivity disorder (ADHD) requires the presence of impairment alongside symptoms above a specific frequency and severity threshold. However, the ...question of whether that symptom threshold represents anything more than an arbitrary cutoff on a continuum of impairment requires further empirical study. Therefore, we present the first study investigating if the relationship between ADHD symptom severity and functional impairment is nonlinear in a way that suggests a discrete, nonarbitrary symptom level threshold associated with a marked step increase in impairment.
Methods
Parent reports on the ADHD‐Rating Scale (ADHD‐RS‐IV), the Weiss Functional Impairment Rating Scale (WFIRS‐P), and the Strengths and Difficulties Questionnaire were collected in a general population sample of 1st, 2nd, and 3rd graders (N = 1,914–2,044).
Results
Piecewise linear regression analyses and nonlinear regression modeling both demonstrated that the relationship between symptom severity (ADHD‐RS‐IV total score) and impairment (WFIRS‐P mean score) was characterized by a gradual linear increase in impairment with higher symptom severity and no apparent step increase or changing rate of increase in impairment at a certain high ADHD‐RS‐IV total score level. Controlling for socioeconomic status, sex, and co‐occurring conduct and emotional symptoms did not alter these results, though comorbid symptoms had a significant effect on impairment.
Conclusions
There was no clear evidence for a discrete, nonarbitrary symptom severity threshold with regard to impairment. The results highlight the continued need to consider both symptoms and impairment in the diagnosis of ADHD.
Background
Preschool hyperactivity is an early risk factor for adult mental health problems and criminality. Little is known about; (a) the patterns of long‐term service costs associated with this ...behavioural marker in the general population and (b) the specific factors predicting hyperactivity‐related costs. We undertook a prospective study investigating associations between preschool hyperactivity and average individual annual service costs up to late adolescent and young adulthood.
Methods
One‐hundred and seventy individuals rated as hyperactive by their parents and 88 nonhyperactive controls were identified from a community sample of 4,215 three years olds. Baseline information about behaviour/emotional problems and background characteristics were collected. At follow‐up (when individuals were aged between 14 and 25 years) information was obtained on service use, and associated costs since the age of three. Based on this information we calculated the average cost per annum incurred by each individual.
Results
Compared to controls, preschoolers with hyperactivity had 17.6 times higher average costs per annum across domains (apart from nonmental health costs). These were £562 for each hyperactive individual compared with £30 for controls. Average annual costs decreased as a function of age, with higher costs incurred at younger ages. The effects of hyperactivity remained significant when other baseline factors were added to the model. Effects were fully mediated by later psychiatric morbidity. When the hyperactive group were examined separately, costs were consistently predicted by male gender and, for some cost codes, by conduct problems.
Conclusions
Preventative approaches targeting early hyperactivity may be of value. Services should be targeted towards high‐risk individuals with careful consideration given to the cost‐to‐benefit trade‐off of early intervention strategies.
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.
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