Article

Validity of the executive function theory of attention-deficit/hyperactivity disorder: A meta-analytic review

Department of Psychology, University of Colorado, Boulder, Colorado 80309, USA.
Biological Psychiatry (Impact Factor: 9.47). 07/2005; 57(11):1336-46. DOI: 10.1016/j.biopsych.2005.02.006
Source: PubMed

ABSTRACT One of the most prominent neuropsychologic theories of attention-deficit/hyperactivity disorder (ADHD) suggests that its symptoms arise from a primary deficit in executive functions (EF), defined as neurocognitive processes that maintain an appropriate problem-solving set to attain a later goal. To examine the validity of the EF theory, we conducted a meta-analysis of 83 studies that administered EF measures to groups with ADHD (total N = 3734) and without ADHD (N = 2969). Groups with ADHD exhibited significant impairment on all EF tasks. Effect sizes for all measures fell in the medium range (.46-.69), but the strongest and most consistent effects were obtained on measures of response inhibition, vigilance, working memory, and planning. Weaknesses in EF were significant in both clinic-referred and community samples and were not explained by group differences in intelligence, academic achievement, or symptoms of other disorders. ADHD is associated with significant weaknesses in several key EF domains. However, moderate effect sizes and lack of universality of EF deficits among individuals with ADHD suggest that EF weaknesses are neither necessary nor sufficient to cause all cases of ADHD. Difficulties with EF appear to be one important component of the complex neuropsychology of ADHD.

2 Bookmarks
 · 
240 Views
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Although attention-deficit hyperactivity disorder (ADHD) is commonly reported after moderate and severe traumatic brain injury (TBI), research is struggling to find a strong link between mild TBI or concussion and ADHD. Epidemiological studies often generate conflicting results which may be related to the difficulty identifying the lingering symptoms of mTBI, the lack of baseline knowledge and the possible exacerbation of pre-existing ADHD symptomology, and/or differential diagnostic criteria for secondary ADHD. The purpose of this study was to determine if a mild TBI/concussion in the juvenile period (postnatal day 30) could induce ADHD-like symptoms in young rodents. Using the Go/No-Go paradigm of the 5-choice serial reaction task, sustained attention, impulsivity, and response inhibition was measured. The open field was also used to measure activity levels at two time points. Animals that experienced a mTBI in the juvenile period exhibited ADHD symptomology, with sex-differences present on one of the tasks. Significant deficits were identified in sustained attention, response inhibition, and impulsivity. Immediately after the mTBI, all rats were hypoactive in the open field, and while male animals exhibited a trend toward hyperactivity in the long-term, females continued to trend towards hypoactivity for the duration of the experiment. These findings provide a unique platform upon which preventative and therapeutic strategies can be implemented and tested in an effort to improve ADHD-like symptoms following mTBI. Copyright © 2015. Published by Elsevier B.V.
    Behavioural Brain Research 03/2015; 286. DOI:10.1016/j.bbr.2015.03.010 · 3.39 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Attention deficit/hyperactivity disorder (ADHD) in children has been associated with attentional and executive problems, but also with socioemotional difficulties possibly associated with deficits in Theory of Mind (ToM). Socioemotional problems in ADHD are associated with more negative prognoses, notably interpersonal, educational problems, and an increased risk of developing other psychiatric disorders that emphasize the need to clarify the nature of their ToM deficits. In this study, we hypothesized that ToM dysfunction in children with ADHD is largely attributable to their attentional and/or executive deficits. Thirty-one children with ADHD (8-12 years, IQ > 85) and 31 typically developing (TD) children were assessed using executive functions (inhibition, planning, and flexibility) and attentional tasks, as well as two advanced ToM tasks (Reading the Mind in the Eyes and Faux Pas) involving different levels of executive control. Children with ADHD performed more poorly than TD children in attentional, executive function, and ToM tasks. Linear regression analyses conducted in the ADHD group indicated that inhibition scores predicted performance on the "Faux Pas" task the best, while attention scores were the best for predicting performance on the Reading the Mind in the Eyes task. When controlled for inhibition and attentional variables, ToM performance in children with ADHD was actually similar to TD children. Contrarily, controlling for ToM scores did not normalize performance for inhibition and attentional tasks in children with ADHD. This unidirectional relationship suggests that deficits in the EF and attentional domains are responsible for ToM deficits in ADHD, which therefore may contribute to their socioemotional difficulties.
    Child Neuropsychology 03/2015; DOI:10.1080/09297049.2015.1012491 · 2.18 Impact Factor

Preview

Download
19 Downloads
Available from