Deficient reinforcement learning in medial frontal cortex as a model of dopamine-related motivational deficits in ADHD.

Attention Deficit/Hyperactivity Disorder (ADHD) is a pathophysiologically complex and heterogeneous condition with both cognitive and motivational components. We propose a novel computational hypothesis of motivational deficits in ADHD, drawing together recent evidence on the role of anterior cingulate cortex (ACC) and associated mesolimbic dopamine circuits in both reinforcement learning and ADHD. Based on findings of dopamine dysregulation and ACC involvement in ADHD we simulated a lesion in a previously validated computational model of ACC (Reward Value and Prediction Model, RVPM).

"Can waiting awaken the resting brain?" A comparison of waiting- and cognitive task-induced attenuation of very low frequency neural oscillations.

The default mode network (DMN) is characterised by coherent very low frequency (VLF) neural oscillations in the resting brain. The attenuation of this activity has been demonstrated following the transition from rest to performance of a broad range of cognitive goal-directed tasks. Whether the activity of resting state VLF oscillations is attenuated during non-cognitive goal-directed tasks such as waiting for rewarding outcomes is not known.

Neural and psychophysiological markers of delay aversion in attention-deficit hyperactivity disorder.

Delay aversion (DAv) is thought to be a crucial factor in the manifestation of impulsive behaviors in patients with attention-deficit/hyperactivity disorder (ADHD). The imposition of delay is predicted to elicit negative emotional reactions in ADHD. The present study offers a multimodal approach to the investigation of DAv.

High loading of polygenic risk for ADHD in children with comorbid aggression.

OBJECTIVE Although attention deficit hyperactivity disorder (ADHD) is highly heritable, genome-wide association studies (GWAS) have not yet identified any common genetic variants that contribute to risk. There is evidence that aggression or conduct disorder in children with ADHD indexes higher genetic loading and clinical severity. The authors examine whether common genetic variants considered en masse as polygenic scores for ADHD are especially enriched in children with comorbid conduct disorder.

Domain-general and domain-specific aspects of temporal discounting in children with ADHD and autism spectrum disorders (ASD): a proof of concept study.

It has been shown that delayed consumable rewards are discounted to a higher degree than money, which has been referred to as the "domain effect". Until now the effects of reward type on temporal discounting (TD) have mainly been studied in adults. Although there is evidence that children with attention-deficit/hyperactivity disorder (ADHD) tend to show steeper TD of money than typically developing peers or children with autism spectrum disorders (ASD), it remains untested whether the domain effect is also seen in children with ADHD and ASD.

Barriers to, and facilitators of, parenting programmes for childhood behaviour problems: a qualitative synthesis of studies of parents' and professionals' perceptions.

Disruptive behaviour problems (DBPs) during childhood exert a high burden on individuals, families and the community as a whole. Reducing this impact is a major public health priority. Early parenting interventions are recommended as valuable ways to target DBPs; however, low take-up of, and high drop-out rates from, these programmes seriously reduce their effectiveness.

Specificity of basic information processing and inhibitory control in attention deficit hyperactivity disorder.

Background: Both inhibitory-based executive functioning (IB-EF) and basic information processing (BIP) deficits are found in clinic-referred attention deficit hyperactivity disorder (ADHD) samples. However, it remains to be determined whether: (1) such deficits occur in non-referred samples of ADHD; (2) they are specific to ADHD; (3) the co-morbidity between ADHD and oppositional defiant disorder/conduct disorder (ODD/CD) has additive or interactive effects; and (4) IB-EF deficits are primary in ADHD or are due to BIP deficits.

Method: We assessed 704 subjects (age 6-12 years) from a non-referred sample using the Development and Well-Being Assessment (DAWBA) and classified them into five groups: typical developing controls (TDC; n = 378), Fear disorders (n = 90), Distress disorders (n = 57), ADHD (n = 100), ODD/CD (n = 40) and ADHD+ODD/CD (n = 39).

The Impact of Idle Time in the Classroom: Differential Effects on Children With ADHD.

Objective: Studies have identified an exacerbation of ADHD deficits under specific laboratory conditions. Less is known about the significance of such contextual factors in relation to everyday functioning in naturalistic settings.

Method: This study investigated the differential impact of classroom "idle time"--periods when students are not actively engaged or waiting for a task--on the behavior of 31 children with ADHD (25 boys and 6 girls; aged 6-12 years) and 31 sex- and age-matched typically developing classmates, who were simultaneously observed in their normal classroom during two school days.

An inventory of European data sources for the long-term safety evaluation of methylphenidate.

To compile an inventory of European healthcare databases with potential to study long-term effects of methylphenidate (MPH) in patients with attention deficit hyperactivity disorder (ADHD). Potential databases were identified through expert opinion, the website of the European Network of Centres for Pharmacoepidemiology and Pharmacovigilance, and literature search. An online survey was conducted among database providers/coordinators to ascertain the databases' appropriateness for inclusion into the inventory.

What influences clinicians' decisions about ADHD medication? Initial data from the Influences on Prescribing for ADHD Questionnaire (IPAQ).

Despite evidence for its efficacy and effectiveness, the use of medication for the treatment of ADHD remains controversial. Little is known about the factors that influence clinicians' decisions to use medication for ADHD. Here, we present initial data on the attitudes of prescribing clinicians from the Influences on Prescribing for ADHD Questionnaire (IPAQ)-a new clinician-completed, 40-item scale.

No Evidence for Inhibitory Deficits or Altered Reward Processing in ADHD: Data From a New Integrated Monetary Incentive Delay Go/No-Go Task.

Objective: Cognitive and motivational factors differentially affect individuals with mental health problems such as ADHD. Here we introduce a new task to disentangle the relative contribution of inhibitory control and reward anticipation on task performance in children with ADHD and/or autism spectrum disorders (ASD).

Method: Typically developing children, children with ADHD,  ASD, or both disorders worked during separate sessions for monetary or social rewards in go/no-go tasks with varying inhibitory load levels.

Nonpharmacological interventions for ADHD: systematic review and meta-analyses of randomized controlled trials of dietary and psychological treatments.

Objective: Nonpharmacological treatments are available for attention deficit hyperactivity disorder (ADHD), although their efficacy remains uncertain. The authors undertook meta-analyses of the efficacy of dietary (restricted elimination diets, artificial food color exclusions, and free fatty acid supplementation) and psychological (cognitive training, neurofeedback, and behavioral interventions) ADHD treatments.

Method: Using a common systematic search and a rigorous coding and data extraction strategy across domains, the authors searched electronic databases to identify published randomized controlled trials that involved individuals who were diagnosed with ADHD (or who met a validated cutoff on a recognized rating scale) and that included an ADHD outcome.

The effects of monetary and social rewards on task performance in children and adolescents: liking is not enough.

The current study compared the effects of reward anticipation on task performance in children and adolescents (8-16 years old) using monetary and various social rewards. Eighty-five typically developing children undertook the Monetary Incentive Delay (MID) task. Of these 44 also undertook the Social Incentive Delay (SID-basic) task where social reward was operationalized as a smiling face and spoken compliments.

Temporal discounting of monetary rewards in children and adolescents with ADHD and autism spectrum disorders.

It has been difficult to differentiate attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in terms of some aspects of their cognitive profile. While both show deficits in executive functions, it has been suggested that they may differ in their response to monetary reward. For instance, children with ADHD prefer small immediate over large delayed rewards more than typically developing controls.

A meta-analytic study of event rate effects on Go/No-Go performance in attention-deficit/hyperactivity disorder.

Background: According to the state regulation deficit model, event rate (ER) is an important determinant of performance of children with attention-deficit/hyperactivity disorder (ADHD). Fast ER is predicted to create overactivation and produce errors of commission, whereas slow ER is thought to create underactivation marked by slow and variable reaction times (RT) and errors of omission.

Methods: To test these predictions, we conducted a systematic search of the literature to identify all reports of comparisons of ADHD and control individuals' performance on Go/No-Go tasks published between 2000 and 2011.

Neuronal oscillations in the EEG under varying cognitive load: a comparative study between slow waves and faster oscillations.

Objective: This study has been specifically designed to investigate very low frequency neuronal oscillations (VLFO, <0.5 Hz) during resting states and during goal-directed tasks of graded difficulty levels, quantify the changes that the slow waves undergo in these conditions and compare them with those for higher frequency bands (namely delta, theta and alpha).

Methods: To this end we developed a multistage signal processing methodology comprising blind source separation coupled with a neural network based feature extraction and classification method.

Neuropsychological correlates of emotional lability in children with ADHD.

Background: Emotional lability (EL) is commonly seen in patients with attention-deficit/hyperactivity disorder (ADHD). The reasons for this association remain currently unknown. To address this question, we examined the relationship between ADHD and EL symptoms, and performance on a range of neuropsychological tasks to clarify whether EL symptoms are predicted by particular cognitive and/or motivational dysfunctions and whether these associations are mediated by the presence of ADHD symptoms.

Longitudinal studies using a "natural experiment" design: the case of adoptees from Romanian institutions.

Objective: To summarize the advantages and limitations of general population, high-risk and "natural experiment" longitudinal studies for studying psychological change. The English and Romanian Adoptees study is used as an example of a "natural experiment," and detailed findings are provided.

Method: What is new is a focus on the young people who spent the whole of their life in institutional care up to the time of adoption and who did not show subnutrition.

An electrophysiological monetary incentive delay (e-MID) task: a way to decompose the different components of neural response to positive and negative monetary reinforcement.

Background: The ability to anticipate and then secure future rewards and avoid future punishments by responding effectively to environmental demands is at the core of successful decision making. Disruptions to these processes have been shown to be implicated in a number of psychiatric conditions. In the current paper we use the electrophysiological monetary incentive delay task (e-MID) to decompose the neural response to (i) reinforcement anticipation, (ii) reinforcement-contingent target processing and (iii) reinforcement-related feedback.