Ventral–striatal responsiveness during reward anticipation in ADHD and its relation to trait impulsivity in the healthy population: A meta-analytic review of the fMRI literature

Abstract

A review of the existing functional magnetic resonance imaging (fMRI) studies on reward anticipation in patients with attention-deficit/hyperactivity disorder (ADHD) is provided. Meta-analysis showed a significant medium effect size (Cohen’s d = 0.48–0.58) in terms of ventral–striatal (VS)-hyporesponsiveness in ADHD. Studies on VS-responsiveness and trait impulsivity in the healthy population demonstrate the opposite relationship, i.e. impulsivity-scores positively correlated with VS activation during reward processing. Against the background that ADHD may represent an extreme on a continuum of normal variability, the question arises as to how these contrasting findings can be integrated. We discuss three theoretical approaches, each of which integrates the opposing findings: (1) an inverted-u-shape model; (2) a (genetic) moderator model; and (3) the “unrelated model”. We conclude that at the present stage the number of existing studies in the healthy population as well as in ADHD groups is too small for a final answer. Therefore, our presented integrative approaches should be understood as an attempt to frame future research directions by generating testable hypotheses and giving practical suggestions for future studies.

Future Directions in Emotion Dysregulation and Youth Psychopathology

“…If relations between externalizing symptoms and RSA are different at the extremes of the normal distribution, such a difference will be swamped in normative samples by individual variation among those whose scores fall much closer to the mean (see Beauchaine, 2009). Similar nonlinearities have been described in other neurobiological systems (e.g., Plichta & Scheres, 2014). A recommendation for future research is to identify possible alternative mechanisms of RSA-behavior relations among normative versus clinical samples and to look for differential relations in the tail of the externalizing distribution when sample size permits.…”

“…Numerous studies indicate that trait impulsive, male children and adolescents with ADHD exhibit hypo-responding in the ventral striatum, a subcortical structure implicated in trait impulsivity (for a review, see Plichta & Scheres, 2014). However, few studies have evaluated prefrontal modulation of striatal responding among those with ADHD (for an exception, see Sauder et al, 2009).…”

A translational neuroscience perspective on mindfulness meditation as a prevention strategy

“…Hypofunction of the brain regions including the cingulo-frontal-parietal cognitive attention network has been consistently observed across studies [35]. A meta-analysis also showed a ventral-striatal hyporesponsiveness (decreased response) on reward anticipation in ADHD individuals compared to healthy individuals [36]. These are major components of neural systems related to attention and self-control networks, motor systems, and reward/feedback-based processing systems.…”

“…The ADHD neuroimaging research related to these network dysfunctions is also associated with the core symptoms of inattention, impulsivity, and hyperactivity. However, these network abnormalities are not the only factors responsible for ADHD; instead, they are only part of the pathophysiology of ADHD [36]. In order to fully characterize the disorder, a next step for neuroscience researchers in this area is to expand their investigation beyond dysfunction of prefrontal-striatal circuitry, to consider the large-scale neural systems involved in ADHD including frontoparietal, dorsal attentional, motor, visual, and default networks [33,37].…”

PHDA: Afinal, qual a sua origem? Uma revisão dos fatores etiológicos

“…O circuito frontoparietal medeia os processos executivos dirigidos a objetivos, ao passo que a rede ventral da atenção facilita a reorientação da atenção para estímulos externos comportamentais relevantes (Faraone et al, 2015). A título exemplificativo, grande parte dos estudos realizados documenta menor ativação do estriado ventral na antecipação da recompensa em pacientes com PHDA quando comparados com os grupos controlo (Plichta & Scheres, 2014). Além disso, constata-se uma hiperativação dos sistemas visuais, que possivelmente deriva de um funcionamento anormal do córtex frontal e do cíngulo anterior (Cortese et al, 2012).…”