Neuroanatomical Abnormalities in Adolescents With Attention-Deficit/Hyperactivity Disorder

Abstract

Objective-Several neuroanatomic abnormalities have been reported in individuals with ADHD. However, findings are not always consistent, perhaps because of heterogeneous subject samples. Studying youths with documented familial ADHD provides an opportunity to examine a more homogeneous population.Method-N=24 youths with a confirmed history of familial ADHD and 10 control youths underwent high-resolution structural Magnetic Resonance Imaging (MRI) examinations. Archived MRI scan data from 12 control youths were included in the analysis to increase statistical power. Individually drawn Region of Interest (ROI) methods were used to examine the frontal lobe gyri and caudate.Results-Cerebral total tissue was similar between groups. The volumes of the right caudate and right inferior frontal lobe were larger in the ADHD youth compared to the control youth. Data from a subgroup of the ADHD youth suggest that increasing left caudate volume is associated with decreasing functional activation of this region.Conclusions-Because previous studies have focused primarily on younger subjects or used an extended age range, the present results may reflect neurodevelopmental changes specific to late adolescence in familial ADHD.

Smaller volumes of caudate nuclei in prepubertal children with ADHD: Impact of age

“…In addition, covariance analyses revealed that age-adjusted caudate volumes were reduced in the ADHD group, but only for children up to 8.0 years. The current findings are consistent with previous reports in children of a similar age range (Qiu et al, 2009;Tremols et al, 2008) and of a younger age range (Mahone et al, 2011), but opposite to findings in older children (adolescents) with ADHD who displayed larger caudate volumes (Garret et al, 2008). Finally, a positive correlation between age and caudate:cerebrum ratios was present in the younger age subgroup (ADHD and controls combined), indicating that caudate volumes increased with age during this developmental period irrespective of clinical status; this correlation was opposite (negative) in the older age subgroup but only in children with ADHD, indicating a decrease in caudate volumes in the clinical group during this age range.…”

“…Different studies have reported that the caudate nuclei of children with ADHD are larger than (Garret et al, 2008;Mataro et al, 1997), smaller than (Castellanos et al, 2003;Hynd et al, 1993;Mahone et al, 2011;Qiu et al, 2009;Semrud-Clikeman et al, 2000) or equal to (Hill et al, 2003) those of normal controls. In addition, the typical asymmetry of the caudate nucleus (right > left) has been reported to be either absent or reversed in children with ADHD (Tremols et al, 2008;Uhlikova et al, 2007).…”

Striatal volumes in pediatric bipolar patients with and without comorbid ADHD

“…A recent DTI study also suggests normalization of the caudate during late adolescence (Silk et al, 2009). This is consistent with findings of increased caudate volume in older adolescents (ages 15 to 19) with ADHD (Mataro et al, 1997; Garrett et al, 2008). Thus, our findings of smaller caudate volumes in children with ADHD are consistent with previous reports in early/mid adolescence, as our subjects had a mean age of 13.4 +/− 3 years.…”

Physical Exercise Alleviates ADHD Symptoms: Regional Deficits and Development Trajectory

“…McAlonan et al (2007) observed deficits within a predominantly right hemispheric frontal-pallidalparietal gray matter network and bilateral white matter tracts in 28 male ADHD children, compared with 31 matched controls. In contrast, in a study of 24 youths with a history of ADHD and 10 healthy age-matched controls, Garrett et al (2008) found similar total cerebral tissue between groups but greater right caudate and right inferior frontal lobe volumes in the ADHD group. Several studies point toward the heritability of frontostriatal structures among ADHD individuals with disruptions in frontostriatal white matter tracts: even after controlling for age, fractional anisotropy in right prefrontal fiber tracts correlated with both functional activity in the inferior frontal gyrus and caudate nucleus, and performance of a go/no go task in parent-child dyads with ADHD (Casey et al 2007).…”