Cortical morphology as a shared neurobiological substrate of attention-deficit/hyperactivity symptoms and executive functioning: a population-based pediatric neuroimaging study

Abstract

IntroductionNeurodevelopmental disorders have repeatedly been associated with poor cognitive functioning and lower levels of general intelligence in both clinical and epidemiological population-based samples.1,2 Studies of attention-deficit/ hyperactivity disorder (ADHD) have shown moderate correlations between ADHD symptom scores and IQ scores and a significantly lower mean IQ in children with ADHD.3,4 Yet, it is unclear whether these deficits in cognitive functioning represent a general cognitive deficit, or whether they primarily reflect deficits in more specific cognitive domains. In order to parse out the specific cognitive problems, multiple studies have tested neuropsychological performance in clinical ADHD samples. These studies suggest that a wide range of neuropsychological domains is affected in patients with ADHD.3,5-7 Yet, 2 large meta-analyses demonstrated that ADHD seems most strongly associated with tasks assessing executive functioning (EF). 3,6 Genetic studies have demonstrated a shared etiology of cognitive ability and child psychopathology in general and, more specifically, in children with ADHD. 4,8 This shared genetic background suggests that a common neurobiology under lies ADHD and cognition. Previous neuroimaging studies in ADHD have shown a delay in brain maturation 9 and a thinner cortex 10 throughout most of the cerebrum. In population-based pediatric samples of both healthy children 11 and the population at large 12 the latter association has Background: Attention-deficit/hyperactivity symptoms have repeatedly been associated with poor cognitive functioning. Genetic studies have demonstrated a shared etiology of attention-deficit/hyperactivity disorder (ADHD) and cognitive ability, suggesting a common underlying neuro biology of ADHD and cognition. Further, neuroimaging studies suggest that altered cortical development is related to ADHD. In a large population-based sample we investigated whether cortical morphology, as a potential neurobiological substrate, underlies the association between attention-deficit/hyperactivity symptoms and cognitive problems. Methods: The sample consisted of school-aged children with data on attention-deficit/hyperactivity symptoms, cognitive functioning and structural imaging. First, we investigated the association between attentiondeficit/hyperactivity symptoms and different domains of cognition. Next, we identified cortical correlates of attention-deficit/hyperactivity symptoms and related cognitive domains. Finally, we studied the role of cortical thickness and gyrification in the behaviour-cognition associations. Results:We included 776 children in our analyses. We found that attention-deficit/hyperactivity symptoms were associated specifically with problems in attention and executive functioning (EF; b = -0.041, 95% confidence interval [CI] -0.07 to -0.01, p = 0.004). Cortical thickness and gyrification were associated with both attention-deficit/hyperactivity symptoms and EF in brain regions that have been previously implicated in ADHD. This partl...

Inattention and Reaction Time Variability Are Linked to Ventromedial Prefrontal Volume in Adolescents

“…Following from a dimensional conceptualization of psychopathology, it is reasonable to postulate that both clinical and normative levels of a given psychiatric syndrome will be underpinned by overlapping neural substrates. Mous et al (2014) recently reported that cortical thickness in bilateral postcentral gyri was negatively associated with parent-reported attention problems in a population-based sample of 444 6- to 8-year-old children (19). Ducharme et al (2012) found that subclinical attention problems in typically developing youths, ranging from 6 to 18 years of age, were associated with a decreased rate of cerebral cortical thinning within prefrontal and parietal cortical regions—brain areas that have been implicated in the pathophysiology of clinically significant attention problems (i.e., ADHD) (20–22).…”

Functional neuroimaging in Tourette syndrome: recent perspectives

“…In patients with OCD, abnormalities of cortico-striatal circuits that involve the orbitofrontal cortex, anterior cingulate cortex, prefrontal cortices, temporo-parieto-occipital areas, thalamus, and the striatum have been suggested, 81,82 as well as impaired striatal connectivity. 83 In patients with ADHD, dysfunctions in the cortico-striatal-thalamo-cortical circuits, 84 changes in cortical thickness and gyrification, 85 changes in the serotonin transporter binding potential, 86 changes in callosal thickness, 87 and reduced gray matter volumes in various regions of the brain are seen. 88,89 In addition, the severity of ADHD and OCD symptoms probably has neuroanatomical correlates.…”

Cortical gyrification and its relationships with molecular measures and cognition in children with the FMR1 premutation

“…Hypergyrification in the temporal, parietal, and frontal regions has been reported in young adults with generalized anxiety disorder 53 while hypogyrification in the similar frontoparietal to temporal regions has been reported in another study of young adults with panic disorder 54 . Hypogyrification in the frontal, temporal, and parietal regions has been reported in cross-sectional studies of children with ADHD 55,56 , but no group difference or LGI and PSI in a cluster peaked at right posterior cingulate cortex in male PM carriers. (e) The positive correlation between SA and PSI in a cluster peaked at the right rostral middle frontal cortex in 15 male PM carriers all scanned using an 8-channel headcoil.…”

“…Hypergyrification in the temporal, parietal, and frontal regions has been reported in young adults with generalized anxiety disorder 53 while hypogyrification in the similar frontoparietal to temporal regions has been reported in another study of young adults with panic disorder 54 . Hypogyrification in the frontal, temporal, and parietal regions has been reported in cross-sectional studies of children with ADHD 55 , 56 , but no group difference or age-related change were observed in a large longitudinal study of 234 children with ADHD compared with 231 typically developing children 57 . Both hyper- and hypo-gyrification in different cortical regions have been reported in children with autism quantified using Freesurfer 58 , 59 .…”