A Meta-Analysis of Working Memory Impairments in Children With Attention-Deficit/Hyperactivity Disorder

doi:10.1097/01.chi.0000153228.72591.73

Journal of the American Academy of Child & Adolescent Psychiatry

Volume 44, Issue 4, April 2005, Pages 377-384

https://doi.org/10.1097/01.chi.0000153228.72591.73 Get rights and content

ABSTRACT

Objective

To determine the empirical evidence for deficits in working memory (WM) processes in children and adolescents with attention-deficit/hyperactivity disorder (ADHD).

Method

Exploratory meta-analytic procedures were used to investigate whether children with ADHD exhibit WM impairments. Twenty-six empirical research studies published from 1997 to December, 2003 (subsequent to a previous review) met our inclusion criteria. WM measures were categorized according to both modality (verbal, spatial) and type of processing required (storage versus storage/manipulation).

Results

Children with ADHD exhibited deficits in multiple components of WM that were independent of comorbidity with language learning disorders and weaknesses in general intellectual ability. Overall effect sizes for spatial storage (effect size = 0.85, CI = 0.62 − 1.08) and spatial central executive WM (effect size = 1.06, confidence interval = 0.72-1.39) were greater than those obtained for verbal storage (effect size = 0.47, confidence interval = 0.36-0.59) and verbal central executive WM (effect size = 0.43, confidence interval = 0.24-0.62).

Conclusion:

Evidence of WM impairments in children with ADHD supports recent theoretical models implicating WM processes in ADHD. Future research is needed to more clearly delineate the nature, severity, and specificity of the impairments to ADHD.

Section snippets

METHOD

A literature search was conducted to identify published studies in which WM was assessed in children and adolescents with ADHD. Medline and PsycINFO were searched from 1997 to December 2003 (subsequent to a previous review by Pennington and Ozonoff [1996]) using combinations of the specific MeSH terms (ADHD, attention deficit disorder, hyperactivity) with the keywords (WM, verbal span, spatial span, short-term memory, phonological loop, visual-spatial sketchpad, digit span). The reference lists

Study Characteristics

Thirty-two studies were located, but only 26 studies met our inclusion criteria. (An appendix containing the descriptive characteristics of the studies is available on the Journal's Web Site at www.jaacap.com via the ArticlePlus feature). The majority of the studies focused on children younger than the age of 13 years, with only six studies examining WM processes in adolescents. Diagnostic criteria varied considerably across the studies within each WM domain. Overall, 15 of the 26 studies used

DISCUSSION

One of the advantages of meta-analysis is that it permits the pooling of results across studies and thus provides greater power to detect group differences. Overall, the findings suggest that WM processes are impaired in children with ADHD. Specifically, marked reductions in performance relative to normal controls were found for both the spatial storage and spatial CE WM components. In contrast, modest deficits were found for verbal storage and verbal CE WM domains. There are several possible

REFERENCES (92)

AC Bedard et al.
Methylphenidate improves visual-spatial memory in children with attention deficit hyperactivity disorder
J Am Acad Child Adolesc Psychiatry
(2004)
TS Braver et al.
A parametric study of prefrontal cortex involvement in human working memory
Neuroimage
(1997)
M Daneman et al.
Individual differences in working memory and reading
J Verb Learn Verb Behav
(1980)
R DerSimonian et al.
Meta-analysis in clinical trials
Control Clin Trials
(1986)
B Gottwald et al.
Does the cerebellum contribute to specific aspects of attention?
Neuropsychologia
(2003)
C *Karatekin et al.
Working memory in childhood-onset schizophrenia and attention-deficit/hyperactivity disorder
Psychiatry Res
(1998)
H Kondo et al.
Functional roles of the cingulo-frontal network in performance on working memory
Neuroimage
(2004)
VS Mattay et al.
Effects of dextroamphetamine on cognitive performance and cortical activation
Neuroimage
(2000)
M *Oie et al.
Contrasts in memory functions between adolescents with schizophrenia or ADHD
Neuropsychologia
(1999)
MC Passolunghi et al.
Short-term memory, working memory, and inhibitory control in children with difficulties in arithmetic problem solving
J Exp Child Psychol
(2001)

LJ *Seidman et al.

A pilot study of neuropsychological function in girls with ADHD

J Am Acad Child Adolesc Psychiatry

(1997)

HL Swanson et al.

Individual differences in children's working memory and writing skill

J Exp Child Psychol

(1996)

HL Swanson

Reading comprehension and working memory in learning-disabled readers: is the phonological loop more important than the executive system?

J Exp Child Psychol

(1999)

R Tannock et al.

Differential effects of methylphenidate on working memory in ADHD children with or without comorbid anxiety

J Am Acad Child Adolesc Psychiatry

(1995)

JW *Adams et al.

Executive function and reading impairments in children reported by their teachers as ‘hyperactive.’

Br J Dev Psychol

(2001)

CJ Aman et al.

A neuropsychological examination of the underlying deficit in attention deficit hyperactivity disorder: frontal lobe versus right parietal lobe theories

Dev Psychol

(1998)

AFT Arnsten

Dopaminergic and noradrenergic influences on cognitive functions mediated by prefrontal cortex

E Awh et al.

The role of spatial selective attention in working memory for locations: evidence from event-related potentials

J Cogn Neurosci

(2000)

A Baddeley

Working Memory

(1986)

A Baddeley

The fractionation of working memory

Proc Natl Acad Sci U S A

(1996)

A Baddeley et al.

The phonological loop as a language learning device

Psychol Rev

(1998)

R Barkley

Attention-Deficit Hyperactivity Disorder: A Handbook for Diagnosis and Treatment

(1990)

R Barkley et al.

Comprehensive evaluation of attention deficit disorder with and without hyperactivity as defined by research criteria

J Consult Clin Psychol

(1990)

R Barkley

Behavioral inhibition, sustained attention, and executive function: constructing a unified theory of ADHD

Psychol Bull

(1997)

RA *Barkley et al.

Executive functioning, temporal discounting, and sense of time in adolescents with attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD)

J Abnorm Child Psychol

(2001)

R Barnett et al.

Abnormal executive function in attention deficit hyperactivity disorder: the effect of stimulant medication and age on spatial working memory

Psychol Med

(2001)

J Biederman et al.

Current concepts on the neurobiology of ADHD

J Atten Disord

(2002)

M Borenstein et al.

Comprehensive Meta-Analysis: Version 1.0

(2001)

SA Bunge et al.

Prefrontal regions are involved in keeping information in and out of mind

Brain

(2001)

S *Cairney et al.

Contextual abnormalities of saccadic inhibition in children with attention deficit hyperactivity disorder

Exp Brain Res

(2001)

FX Castellanos et al.

Developmental trajectories of brain volume abnormalities in children and adolescents with attention-deficit/hyperactivity disorder

JAMA

(2002)

J Cohen

Statistical Power Analysis for the Behavioral Sciences

(1988)

M Daneman et al.

Working memory and language comprehension: a meta-analysis

Psychon Bull Rev

(1996)

P Dawson et al.

Executive Skills in Children and Adolescents: A Practical Guide to Assessment and Intervention

(2004)

S Durston

A review of the biological bases of ADHD: what have we learned from imaging studies?

Ment Retard Dev Disabil Res Rev

(2003)

M Egger et al.

Bias in meta-analysis detected by a simple, graphical test

BMJ

(1997)

PC Fletcher et al.

Frontal lobes and human memory: insights from functional neuroimaging

Brain

(2001)

SE Gathercole et al.

Working memory deficits in children with low achievements in the national curriculum at 7 years of age

Br J Educ Psychol

(2000)

SE Gathercole et al.

Working memory skills and educational attainment: evidence from national curriculum assessments at 7 and 14 years of age

Appl Cogn Psychol

(2004)

JN Giedd et al.

Brain imaging of attention deficit hyperactivity disorder

Ann N Y Acad Sci

(2001)

PS Goldman-Rakic et al.

Targeting the dopamine D (1) receptor in schizophrenia: insights for cognitive dysfunction

Psychopharmacol (Berl)

(2004)

JPT Higgins et al.

Quantifying heterogeneity in a meta-analysis

Stat Med

(2002)

JPT Higgins et al.

Measuring inconsistency in meta-analyses

BMJ

(2003)

M Hoskyn et al.

The relationship between working memory and writing in younger and older adults

Reading Writing

(2003)

HL Jarvis et al.

Verbal and non-verbal working memory and achievements on national curriculum tests at 11 and 14 years

Educ Child Psychol

(2003)

Cited by (981)

Memory deficits and hippocampal cytokine expression in a rat model of ADHD
2024, Brain, Behavior, and Immunity - Health
Attention-deficit/hyperactivity disorder (ADHD) is a complex behavioral disorder characterized by hyperactivity, impulsivity, inattention, and deficits in working memory and time perception. While animal models have advanced our neurobiological understanding of this condition, there are limited and inconsistent data on working and elapsed time memory function. Inflammatory signaling has been identified as a key factor in memory and cognitive impairments, but its role in ADHD remains unclear. Additionally, the disproportionate investigation of male subjects in ADHD research has contributed to a poor understanding of the disorder in females. This study sought to investigate the potential connections between memory, neuroimmunology, and ADHD in both male and female animals. Specifically, we utilized the spontaneously hypertensive rat (SHR), one of the most extensively studied animal models of ADHD. Compared to their control, the Wistar-Kyoto (WKY) rat, male SHR are reported to exhibit several behavioral phenotypes associated with ADHD, including hyperactivity, impulsivity, and poor sustained attention, along with impairments in learning and memory. As the hippocampus is a key brain region for learning and memory, we examined the behavior of male and female SHR and WKY rats in two hippocampal-dependent memory tasks. Our findings revealed that SHR have delay-dependent working memory deficits that were similar to, albeit less severe than, those seen in hippocampal-lesioned rats. We also observed impairments in elapsed time processing in female SHR, particularly in the discrimination of longer time durations. To investigate the impact of inflammatory signaling on memory in these rats, we analyzed the levels of several cytokines in the dorsal and ventral hippocampus of SHR and WKY. Although we found some sex and genotype differences, concentrations were generally similar between groups. Taken together, our results indicate that SHR exhibit deficits in spatial working memory and memory for elapsed time, as well as some differences in hippocampal cytokine concentrations. These findings contribute to a better understanding of the neurobiological basis of ADHD in both sexes and may inform future research aimed at developing effective treatments for the disorder. Nonetheless, the potential mediating role of neuroinflammation in the memory symptomatology of SHR requires further investigation.
Fluoride exposure during pregnancy from a community water supply is associated with executive function in preschool children: A prospective ecological cohort study
2023, Science of the Total Environment
On May 19, 2011, Calgary, Canada stopped fluoridating its drinking water. This prospective ecological study examined if maternal exposure to fluoride during pregnancy from drinking water that was fluoridated at the recommended level of 0.7 mg/L was associated with children's intelligence and executive function at 3–5 years of age.
Participants were 616 maternal-child pairs enrolled in the Calgary cohort of the Alberta Pregnancy Outcomes and Nutrition (APrON) study between 2009 and 2012. Maternal-child pairs were classified as fully exposed to fluoridated drinking water throughout pregnancy (n = 295); exposed to fluoridated drinking water for at least part of the pregnancy plus an additional 90 days (n = 220); or not exposed to fluoridated drinking water during pregnancy plus the 90 days prior to pregnancy (n = 101). Children's Full Scale IQs were assessed using the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition: Canadian (WPPSI-IV^CDN). Children's executive functions were also assessed: working memory (WPPSI-IV^CDN Working Memory Index), inhibitory control (Gift Delay, NEPSY-II Statue subtest), and cognitive flexibility (Boy-Girl Stroop, Dimensional Change Card Sort (DCCS)).
No associations were found between exposure group and Full Scale IQ. However, compared to no exposure, full exposure to fluoridated drinking water throughout pregnancy was associated with poorer performance on the Gift Delay (B = 0.53, 95 % CI = 0.31, 0.93). Sex-specific analyses revealed that girls in the fully exposed (AOR = 0.30, 95 % CI = 0.13, 0.74) and partially exposed groups (AOR = 0.42, 95 % CI = 0.17, 1.01) performed more poorly than girls in the not exposed group. Sex effects were also found on the DCCS; girls in the fully exposed (AOR = 0.34, 95 % CI = 0.14, 0.88) and partially exposed groups (AOR = 0.29, 95 % CI = 0.12, 0.73) performed more poorly.
Maternal exposure to drinking water throughout pregnancy fluoridated at the level of 0.7 mg/L was associated with poorer inhibitory control and cognitive flexibility, particularly in girls, suggesting a possible need to reduce maternal fluoride exposure during pregnancy.
Fronto-parietal white matter microstructure associated with working memory performance in children with ADHD
2023, Cortex
Attention Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder with many functional impairments thought to be underpinned by difficulties in executive function domains such as working memory. The superior longitudinal fasciculus (SLF) plays an integral role in the development of working memory in neurotypical children. Neuroimaging research suggests reduced white matter organization of the SLF may contribute to working memory difficulties commonly seen in ADHD. This study aimed to examine the relationship between white matter organization of the SLF and working memory in children with ADHD.
We examined the association of tract volume and apparent fibre density (AFD) of the SLF with working memory in children with ADHD (n = 64) and controls (n = 58) aged 9–11years. Children completed a computerized spatial n-back task and underwent diffusion magnetic resonance imaging (dMRI). Constrained spherical deconvolution-based tractography was used to construct the three branches of the SLF bilaterally and examine volume and AFD of the SLF.
Regression analyses revealed children with ADHD exhibited poorer working memory, and lower volume and AFD of the left SLF-II compared to healthy controls. There was also an association between reaction time and variability (RT and RT-V) and the left SLF-II. Further analyses revealed volume of the left SLF-II mediated the relationship between ADHD and working memory performance (RT and RT-V).
These findings add to the current body of ADHD literature, revealing the potential role of frontoparietal white matter in working memory difficulties in ADHD.
Sustained attention plays a critical role in reading comprehension of adults with and without ADHD
2023, Learning and Individual Differences
The study aims to examine whether individuals with attention deficit hyperactivity disorder (ADHD) have reading comprehension difficulties, and if they do, which cognitive abilities underlie these difficulties. It focuses on the role of sustained attention in reading comprehension.
Fifty adults with ADHD and 57 participants without ADHD performed tasks of short-term memory, vocabulary, and sustained attention, as well as a task of reading comprehension.
The two groups did not differ in short-term memory or vocabulary, but participants with ADHD received lower scores on both the sustained attention and the reading comprehension tasks compared to participants without ADHD. In addition, a regression analysis in which group was entered first and then scores on the cognitive tests showed that only sustained attention predicted reading comprehension.
The findings suggest that sustained attention is critical for reading comprehension and thus it should be incorporated into theoretical models of reading comprehension.
Developmental trajectory of hot and cold executive functions in children with and without attention deficit-hyperactivity disorder (ADHD)
2023, Research in Developmental Disabilities
Children with attention deficit hyperactivity disorder (ADHD) have a delayed development. Two main cognitive models of ADHD are executive (cold) and motivational (hot) models. In this study, we aimed to compare the development of hot and cold executive functions in children with and without ADHD.
Forty-six children with ADHD symptoms (56% boys) and forty-four typically developing controls (54% boys), in three age groups of 6–8, 8–10 and 10–12 years, were participated in the study. Go/No-Go Task (GNGT), One-Back Test (OBT) and Shifting Attention Test (SAT), Delay Discounting Test (DDT) and Balloon Analogue Risk Task (BART) were used for assessment.
Children with ADHD showed lower performance in GNG, OBT, SAT, and BART, but intact performance in DDT. The tasks’ performance was significantly different between three age groups in GNG and SAT, but similar in OBT and BART. The interaction effect was significant only for the BART measures.
Children with ADHD compared to typically developing children, experience impaired hot and cold executive functions. The cognitive delay was found only in risky decision making as a hot executive function.
Exploring the steps of learning: computational modeling of initiatory-actions among individuals with attention-deficit/hyperactivity disorder
2024, Translational Psychiatry

View all citing articles on Scopus

This research was funded by a Canadian Institute of Health Research (CIHR) Doctoral Fellowship (Ms. Martinussen), a CIHR Postdoctoral Fellowship (Dr. Hayden), and a CIHR operating grant (Dr. Tannock).

Article Plus (online only) materials for this article appear on the Journal's Web site: www.jaacap.com.

Correspondence to Dr. Rosemary Tannock, Brain and Behavior Research, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8; e-mail: [email protected].

Disclosure: Dr. Tannock has received research funding from, is a consultant for, and is on the speaker's bureau for Eli Lilly. She is also on the advisory board for Shire and has received funding (for placebo control) from Novartis. The other authors have no financial relationships to disclose.

View full text

ARTICLESA Meta-Analysis of Working Memory Impairments in Children With Attention-Deficit/Hyperactivity Disorder

ABSTRACT

Objective

Method

Results

Conclusion:

Section snippets

METHOD

Study Characteristics

DISCUSSION

J Am Acad Child Adolesc Psychiatry

Neuroimage

J Verb Learn Verb Behav

Control Clin Trials

Neuropsychologia

Psychiatry Res

Neuroimage

Neuroimage

Neuropsychologia

J Exp Child Psychol

J Am Acad Child Adolesc Psychiatry

J Exp Child Psychol

J Exp Child Psychol

J Am Acad Child Adolesc Psychiatry

Executive function and reading impairments in children reported by their teachers as ‘hyperactive.’

Br J Dev Psychol

A neuropsychological examination of the underlying deficit in attention deficit hyperactivity disorder: frontal lobe versus right parietal lobe theories

Dev Psychol

Dopaminergic and noradrenergic influences on cognitive functions mediated by prefrontal cortex

The role of spatial selective attention in working memory for locations: evidence from event-related potentials

J Cogn Neurosci

Working Memory

The fractionation of working memory

Proc Natl Acad Sci U S A

The phonological loop as a language learning device

Psychol Rev

Attention-Deficit Hyperactivity Disorder: A Handbook for Diagnosis and Treatment

Comprehensive evaluation of attention deficit disorder with and without hyperactivity as defined by research criteria

J Consult Clin Psychol

Behavioral inhibition, sustained attention, and executive function: constructing a unified theory of ADHD

Psychol Bull

Executive functioning, temporal discounting, and sense of time in adolescents with attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD)

J Abnorm Child Psychol

Abnormal executive function in attention deficit hyperactivity disorder: the effect of stimulant medication and age on spatial working memory

Psychol Med

Current concepts on the neurobiology of ADHD

J Atten Disord

Comprehensive Meta-Analysis: Version 1.0

Prefrontal regions are involved in keeping information in and out of mind

Brain

Contextual abnormalities of saccadic inhibition in children with attention deficit hyperactivity disorder

Exp Brain Res

Developmental trajectories of brain volume abnormalities in children and adolescents with attention-deficit/hyperactivity disorder

JAMA

Statistical Power Analysis for the Behavioral Sciences

Working memory and language comprehension: a meta-analysis

Psychon Bull Rev

Executive Skills in Children and Adolescents: A Practical Guide to Assessment and Intervention

A review of the biological bases of ADHD: what have we learned from imaging studies?

Ment Retard Dev Disabil Res Rev

Bias in meta-analysis detected by a simple, graphical test

BMJ

Frontal lobes and human memory: insights from functional neuroimaging

Brain

Working memory deficits in children with low achievements in the national curriculum at 7 years of age

Br J Educ Psychol

Working memory skills and educational attainment: evidence from national curriculum assessments at 7 and 14 years of age

Appl Cogn Psychol

Brain imaging of attention deficit hyperactivity disorder

Ann N Y Acad Sci

Targeting the dopamine D (1) receptor in schizophrenia: insights for cognitive dysfunction

Psychopharmacol (Berl)

Quantifying heterogeneity in a meta-analysis

Stat Med

Measuring inconsistency in meta-analyses

BMJ

The relationship between working memory and writing in younger and older adults

Reading Writing

Verbal and non-verbal working memory and achievements on national curriculum tests at 11 and 14 years

Educ Child Psychol

ARTICLES
A Meta-Analysis of Working Memory Impairments in Children With Attention-Deficit/Hyperactivity Disorder