Attention-Deficit/Hyperactivity Disorder and Attention Networks

Abstract

Research attempting to elucidate the neuropathophysiology of attention-deficit/hyperactivity disorder (ADHD) has not only shed light on the disorder itself, it has simultaneously provided new insights into the mechanisms of normal cognition and attention. This review will highlight and integrate this bidirectional flow of information. Following a brief overview of ADHD clinical phenomenology, ADHD studies will be placed into a wider historical perspective by providing illustrative examples of how major models of attention have influenced the development of neurocircuitry models of ADHD. The review will then identify major components of neural systems potentially relevant to ADHD, including attention networks, reward/feedbackbased processing systems, as well as a 'default mode' resting state network. Further, it will suggest ways in which these systems may interact and be influenced by neuromodulatory factors. Recent ADHD imaging data will be selectively provided to both illustrate the field's current level of knowledge and to show how such data can inform our understanding of normal brain functions. The review will conclude by suggesting possible avenues for future research.

Local synchronization and amplitude of the fluctuation of spontaneous brain activity in attention-deficit/hyperactivity disorder: a resting-state fMRI study

“…These circuits are known as the cognitive-attentional network, underlying important higher brain functions such as executive control, cognition, selective and divided attention, vigilance and working memory [38,39] . Restingstate [40] and cognitive [41,42] neuroimaging findings have consistently shown hypoactivity in these circuits in ADHD patients.…”

Attention-Deficit/Hyperactivity Disorder–like Phenotype in a Mouse Model with Impaired Actin Dynamics

“…Defects reminiscent of ADHD are displayed by DAT mutant mice, underlining the implication of dopamine dysfunction in the etiology of ADHD (4). Several ADHD susceptibility loci do not contain dopamine-related genes (5)(6)(7)(8)(9), and an increasing number of studies implicate corticostriatal network abnormalities in ADHD (10). These findings, together with the phenotypic heterogeneity of patients with ADHD, suggest the existence of diverse ADHD-associated genes and underlying mechanisms.…”

Inter-hemispherical asymmetry in default-mode functional connectivity and BAIAP2 gene are associated with anger expression in ADHD adults

“…It has a prevalence of 5-8% in childhood (Bush, 2010), and persists in adulthood in 60% of the cases with an established prevalence of 2.5-4.9%, (Simon et al, 2009). Depending on the presence and severity of ADHD cardinal symptoms (i.e., hyperactivity, impulsiveness and inattention), predominantly hyperactive/impulsive, inattentive and combined subtypes have been described Fried et al, 2006;Babinski et al, 2011;Doshi et al, 2012;Chang et al, 2014;Ginsberg et al, 2014).…”