Hostname: page-component-89b8bd64d-r6c6k Total loading time: 0 Render date: 2026-05-09T14:38:59.612Z Has data issue: false hasContentIssue false

Identifying a consistent pattern of neural function in attention deficit hyperactivity disorder: a meta-analysis

Published online by Cambridge University Press:  13 May 2013

H. McCarthy
Affiliation:
Department of Psychiatry, Integrated Neuroimaging, Trinity College Dublin, Dublin, Republic of Ireland Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Republic of Ireland
N. Skokauskas
Affiliation:
Department of Psychiatry, Integrated Neuroimaging, Trinity College Dublin, Dublin, Republic of Ireland Department of Child and Adolescent Psychiatry, Children's University Hospital, Temple Street, Dublin, Republic of Ireland
T. Frodl*
Affiliation:
Department of Psychiatry, Integrated Neuroimaging, Trinity College Dublin, Dublin, Republic of Ireland Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Republic of Ireland
*
* Address for correspondence: T. Frodl, Department of Psychiatry and Institute of Neuroscience, Trinity College Dublin, Lloyd Building, Dublin 2, Republic of Ireland. (Email: thomas.frodl@tcd.ie)

Abstract

Background

The neurobiological underpinnings of attention deficit hyperactivity disorder (ADHD) are inconclusive. Activation abnormalities across brain regions in ADHD compared with healthy controls highlighted in task-based functional magnetic resonance imaging (fMRI) studies are heterogeneous. To identify a consistent pattern of neural dysfunction in ADHD, a meta-analysis of fMRI studies using Go/no-go, Stop and N-back tasks was undertaken.

Method

Several databases were searched using the key words: ‘ADHD and fMRI’ and ‘ADHD and fMRI task’. In all, 20 studies met inclusion criteria comprising 334 patients with ADHD and 372 healthy controls and were split into N-back, Stop task and Go/no-go case–control groups. Using Signed Differential Mapping each batch was meta-analysed individually and meta-regression analyses were used to examine the effects of exposure to methylphenidate (MPH), length of MPH wash-out period, ADHD subtype, age and intelligence quotient (IQ) differences upon neural dysfunction in ADHD.

Results

Across all tasks less activity in frontal lobe regions compared with controls was detected. Less exposure to treatment and lengthier wash-out times resulted in less left medial frontal cortex activation in N-back and Go/no-go studies. Higher percentage of combined-type ADHD resulted in less superior and inferior frontal gyrus activation. Different IQ scores between groups were linked to reduced right caudate activity in ADHD.

Conclusions

Consistent frontal deficits imply homogeneous cognitive strategies involved in ADHD behavioural control. Our findings suggest a link between fMRI results and the potentially normalizing effect of treatment and signify a need for segregated examination and contrast of differences in sample characteristics in future studies.

Information

Type
Original Articles
Copyright
Copyright © Cambridge University Press 2013 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

Supplementary material: File

McCarthy Supplementary Material

Figure S1, Tables A, B, C, S1, S2 and S3

Download McCarthy Supplementary Material(File)
File 419.3 KB