A Review of Cognitive Disorders in Attention Deficit Hyperactivity Disorder with Emphasis on Executive Functions and Brain Structures

Abstract

IntroductionAttention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children whose symptoms were first described by Heinrich Hoffmann in 1863. 1 It is characterized by disruption of inattention, conduct disorder, poor social communication, and hyperactivity/impulsivity. Inattention causes an inability to remain focused on schoolwork, seeming not to listen, and losing things at school more frequently than what is consistent with the child's developmental level. Hyperactivity and impulsivity, on the other hand, result in excess activity, fidgeting, trouble remaining seated, disturbing others' activities, and trouble waiting for one's turn. 2,3 ADHD tends to overlap with other common externalizing disorders in children, such as oppositional disorder and conduct disorder. 4,5 If the condition persists until adulthood, it often leads to social performance deficit as well as educational and professional dysfunctions. 6 Although hyperactivity subsides with age, attention deficit increases in most patients. 7 In most cultures, demographic surveys report a prevalence of nearly 5% and 2.5% in children and adults, respectively. 8 Overall, the disorder affects boys more than girls, with 1.2% and 1.6% higher occurrence during childhood and adulthood, respectively. However, girls are more prone to displaying inattention symptoms. 9 Evidence from various studies in neuropsychology, 10 pathophysiology, 11 genetics, 12 and phenotypes, 13 suggest that several factors with varying levels of intensity manifest clinically as attention deficit and hyperactivity. Since the 1970s, numerous studies have identified impairments in executive functioning as the core cause of ADHD in adolescents. 14 These impairments lead to deficits in essential cognitive abilities for complex goaloriented behaviors and adjusting to a range of changes and environmental demands. 9 several authors 15,16 believed that some, but not all, children with ADHD suffer from significant impairments in several areas of executive functioning; however, other authors such as Brown 17 discussed that ADHD is fundamentally a developmental disorder that affects executive functions (EFs) in all cases. Thus, this paper focuses exclusively on this issue. The aim of this study is to review existing research on cognitive impairments in children with ADHD with a focus on EFs.

The effect of a virtual reality based intervention on processing speed and working memory in individuals with ADHD—A pilot-study

“…The predominant features of ADHD in adults differ from those in children, with fewer symptoms of hyperactivity and impulsivity and more inattention (Hervey et al, 2004;Biederman et al, 2010;Salomone et al, 2020;Roshannia et al, 2021;Plowden et al, 2022). In adults, hyperactivity can be expressed by restlessness, mood swings, involvement in too many activities, racing thoughts, and an inability to relax (Sabhlok et al, 2022).…”

“…However, current evidence states that executive function (EF) deficits are the central components of ADHD (Diamond, 2013;Butzbach et al, 2019;Sabhlok et al, 2022). EFs include processes associated with the prefrontal and thalamic-reticular areas of the brain, which are responsible for initiating, directing, and regulating thoughts, emotions, and behaviors to achieve a desired goal (Pennington, 1988;Al-Yagon, 2018;Roselló et al, 2020;Roshannia et al, 2021). Various deficits in EF are described in children and adults, affecting working memory, cognitive flexibility, processing speed, decisionmaking, problem-solving, verbal fluency, and planning ability (Al-Yagon, 2018;Salomone et al, 2020;Alaghband-Rad et al, 2021;Coelho et al, 2021;Roshannia et al, 2021).…”

“…Deficits in PS also impact less stimulating tasks, leading to procrastination and, consequently, disregard and postponement of their completion (Kibby et al, 2019;Weibel et al, 2020). As a result of these deficits, a range of occupational, academic, and social difficulties arise (Salomone et al, 2020;Roshannia et al, 2021;Sabhlok et al, 2022). These deficits in PS explain, at least in part, why ADHD in adults has a considerable impact on schooling and occupational functioning, and on family and peer relationships.…”

Brain Relatively Inert Network: Taking Adult Attention Deficit Hyperactivity Disorder as an Example

“…However, ADHD is not a child-specific disorder; it is a chronic process with symptoms that last until adulthood, including remission cases, by up to 50% ( Shaw et al, 2013 ; Rovira et al, 2020 ). The common behavioral manifestations of ADHD are attention deficit, hyperactivity, and impulsivity ( Schneider et al, 2006 ; Spencer et al, 2007 ; Roshannia et al, 2021 ). ADHD patients usually present with a variety of concomitant disorders, and they are overlain by one or more concomitant psychological disorders, such as addiction, borderline disorder, depression, bipolar disorder, and anxiety disorders ( Ashcroft et al, 2015 ; Schiweck et al, 2021 ).…”