Basic and complex cognitive functions in Adult ADHD

Abstract

Background Many clinical studies reported deficits in basic and complex cognitive functions in adults with Attention-Deficit/Hyperactivity Disorder (ADHD). However, the extent in which deficits in basic functions (i.e., processing speed and distractibility) contribute to complex cognitive impairments (i.e., working memory, planning, cognitive flexibility, memory functions) in adults with ADHD is not well-studied. So far, literature show only one study, revealing that basic functions explain 27–74% of executive dysfunctions. Yet, the authors reported that findings could be affected by the selection of neuropsychological tests. The goal of the present research is to replicate such a finding using a different sample and a different set of neuropsychological tests. Methods Forty-eight adult patients with ADHD were compared with 48 healthy controls in basic cognitive functions, namely processing speed and distractibility and more complex cognitive functions, namely selective attention, cognitive flexibility, planning, working memory, verbal fluency, and verbal memory. Basic and complex cognitive functions were assessed using the Vigilance and Sustained Attention, Selective Attention, N-Back, Tower of London, Trail Making Test, Word Fluency, and Verbal Learning and Memory. Results and conclusion Logistic regression analyses showed that impairments in complex cognitive functions explained 25% of the variance in ADHD diagnosis. The explained variance dropped from 25% to 9% after considering basic functions of processing speed and distractibility. This 64% reduction highlights the importance of basic functions for impairments in complex functions in patients with ADHD.

Time Perception in Adult ADHD: Findings from a Decade—A Review

“…However, studies have identified various aetiology factors [ 3 , 13 , 14 ]. These include genetic and environmental factors like smoking during pregnancy, stress, infection, poverty, trauma, and exposure to toxicants [ 15 , 16 , 17 , 18 , 19 , 20 ] that can lead to changes in brain structure, catecholaminergic neurotransmission, and to specific symptoms like inhibitory and attentional deficits [ 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. Recent studies have demonstrated that ADHD is associated with various cognitive dysfunctions and structural changes [ 6 , 28 , 29 , 30 , 31 ].…”

Stability of Attention Performance of Adults with ADHD over Time: Evidence from Repeated Neuropsychological Assessments in One-Month Intervals

“…The close relationship between attention and higher-order cognitive functions has been observed in both clinical samples [ 23 , 24 , 25 , 26 ] and non-clinical samples [ 27 , 28 , 29 , 30 ] by numerous studies, suggesting that the development of higher-order cognitive functions may be based on the development of basic attention. More recently, the hierarchical relationship between attention and higher-order cognitive functions was reported in patients with ADHD, which underlines the relevance of attention in ADHD [ 26 , 31 , 32 ]. In this context, research showed that attention might be the foundation of more complex cognitive functions that build upon attention, such as response inhibition, planning, memory, and task-switching.…”

The Moderating Role of Emotional Regulation on the Relationship between School Results and Personal Characteristics of Pupils with Attention Deficit/Hyperactivity Disorder

“…The test contained 60 items grouped into 3 scales—recognition of facial expressions, identification of emotions and identification of emotional response. Content validity was ensured by the selection of images/items based on studies in the field (the relationship between brain and behavior, the identification and understanding of emotions and the social contexts in which they appear) by two experts in child psychological assessment and child development [ 30 , 34 , 35 , 36 , 37 ]. Content adjustment was based on the same principle as selection.…”

“…Mohamed et al [ 34 ] explored whether impairments in core processes (processing speed and distractibility) in individuals with ADHD explain impairments in higher order functions, namely executive functions, memory and complex attention. Hierarchical logistic regression analyses to assess the contribution of core processes to impairments in higher-order functions revealed that deficits in core processes explained 41–43% of deficits in executive functions, 27–29% in memory, and 56–74% in complex attention.…”