Article

The neural correlates of attention deficit hyperactivity disorder: an ALE meta-analysis.

NYU Child Study Center, New York, NY 10016, USA.
Journal of Child Psychology and Psychiatry (Impact Factor: 5.67). 10/2006; 47(10):1051-62. DOI: 10.1111/j.1469-7610.2006.01671.x
Source: PubMed

ABSTRACT Attention deficit/hyperactivity disorder (ADHD) is one of the most prevalent and commonly studied forms of psychopathology in children and adolescents. Causal models of ADHD have long implicated dysfunction in fronto-striatal and frontal-parietal networks supporting executive function, a hypothesis that can now be examined systematically using functional neuroimaging. The present work provides an objective, unbiased statistically-based meta-analysis of published functional neuroimaging studies of ADHD.
A recently developed voxel-wise quantitative meta-analytic technique known as activation likelihood estimation (ALE) was applied to 16 neuroimaging studies examining and contrasting patterns of neural activity in patients with ADHD and healthy controls. Voxel-wise results are reported using a statistical threshold of p < .05, corrected. Given the large number of studies examining response inhibition, additional meta-analyses focusing specifically on group differences in the neural correlates of inhibition were included.
Across studies, significant patterns of frontal hypoactivity were detected in patients with ADHD, affecting anterior cingulate, dorsolateral prefrontal, and inferior prefrontal cortices, as well as related regions including basal ganglia, thalamus, and portions of parietal cortex. When focusing on studies of response inhibition alone, a more limited set of group differences were observed, including inferior prefrontal cortex, medial wall regions, and the precentral gyrus. In contrast, analyses focusing on studies of constructs other than response inhibition revealed a more extensive pattern of hypofunction in patients with ADHD than those of response inhibition.
To date, the most consistent findings in the neuroimaging literature of ADHD are deficits in neural activity within fronto-striatal and fronto-parietal circuits. The distributed nature of these results fails to support models emphasizing dysfunction in any one frontal sub-region. While our findings are suggestive of the primacy of deficits in frontal-based neural circuitry underlying ADHD, we discuss potential biases in the literature that need to be addressed before such a conclusion can be fully embraced.

Download full-text

Full-text

Available from: Francisco Xavier Castellanos, Jul 03, 2015
2 Followers
 · 
84 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: There is evidence that attention-deficit/hyperactivity disorder (ADHD) is associated with linguistic difficulties. However, the pathophysiology underlying these difficulties is yet to be determined. This study investigates functional abnormalities in Broca's area, which is associated with speech production and processing, in adolescents with ADHD by means of resting-state fMRI. Data for the study was taken from the ADHD-200 project and included 267 ADHD patients (109 with combined inattentive/hyperactive subtype and 158 with inattentive subtype) and 478 typically-developing control (TDC) subjects. An analysis of fractional amplitude of low-frequency fluctuations (fALFF), which reflects spontaneous neural activity, in Broca's area (Brodmann Areas 44/45) was performed on the data and the results were compared statistically across the participant groups. fALFF was found to be significantly lower in the ADHD inattentive group as compared to TDC in BA 44, and in the ADHD combined group as compared to TDC in BA 45. The results suggest that there are functional abnormalities in Broca's area with people suffering from ADHD, and that the localization of these abnormalities might be connected to particular language deficits associated with ADHD subtypes, which we discuss in the article. The findings might help explore the underlying causes of specific language difficulties in ADHD. Pikusa, M. and R. Jończyk. In press. " Functional abnormalities in Broca's area in adolescents with ADHD: resting-state fMRI ". PSiCL
    Poznan Studies in Contemporary Linguistics 01/2015; 51(1). DOI:10.1515/psicl-2015-0006
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Resumen Los procesos atencionales son una enorme área de estudio para el investigador en neuropsicología y un elemento de frecuente evaluación para el neuropsicólogo clínico. No obstante, la multiplicidad de términos y teorías relacionados a la atención hacen muchas veces muy difícil la convergencia de los diferentes hallazgos entre los investigadores y el entendimiento entre los neuropsicólogos clínicos. En este artículo se describen algunas de las teorías más relevantes y con mayor solidez científica sobre la atención. Asimismo, se detallan algunas de las patologías más características de las alteraciones de la atención y, finalmente, se desarrollan algunos de los tests mas importantes para su evaluación. Palabras clave: atención-modelos de atención-trastorno por déficit de atención e impulsividad-evaluación. Abstract Attention processes are a huge area of work for the neuropsychology researcher and a cognitive function frequently assessed by the clinical neuropsychologist. However, the multiplicity of definitions and theories related to attention make very hard to match the findings from different researchers in the field and the application of these concepts in the clinical field. In this article the some of the most important and scientifically sound theories on attention as well as some of the most characteristic attention disorders are described. Besides, some of the most important tests for the assessment of attention are explained.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Studies of adults with attention-deficit/hyperactivity disorder (ADHD) have suggested that they have deficient response inhibition, but findings concerning the neural correlates of inhibition in this patient population are inconsistent. We used the Stop-Signal task and functional magnetic resonance imaging (fMRI) to compare neural activation associated with response inhibition between adults with ADHD (N=35) and healthy comparison subjects (N=62), and in follow-up tests to examine the effect of current medication use and symptom severity. There were no differences in Stop-Signal task performance or neural activation between ADHD and control participants. Among the ADHD participants, however, significant differences were associated with current medication, with individuals taking psychostimulants (N=25) showing less stopping-related activation than those not currently receiving psychostimulant medication (N=10). Follow-up analyses suggested that this difference in activation was independent of symptom severity. These results provide evidence that deficits in inhibition-related neural activation persist in a subset of adult ADHD individuals, namely those individuals currently taking psychostimulants. These findings help to explain some of the disparities in the literature, and advance our understanding of why deficits in response inhibition are more variable in adult, as compared with child and adolescent, ADHD patients.
    Psychiatry Research Neuroimaging 04/2014; DOI:10.1016/j.pscychresns.2014.02.002 · 2.83 Impact Factor