Right Caudate Volume and Executive Functions in Children with Attention-Deficit/Hyperactivity Disorder (ADHD)

BackgroundThe caudate and putamen have previously been implicated in Attention-Deficit/Hyperactivity Disorder (ADHD). However, previous studies have not investigated the relationship between the caudate and putamen with executive function (EF). The current study investigated the clinical relevance of the caudate and putamen with respect to EF. MethodWe studied 49 children (24 ADHD/25 typically developing children (TDC)). All participants in the ADHD group had to undergo a 48-hour stimulant medication washout period. Participants completed cognitive tasks related to working memory/inhibition and underwent a T1-weighted MRI sequence. All parents completed behaviour rating scales using the Behavior Rating Inventory of Executive Function, Second Edition (BRIEF-2). Data were analyzed using multivariate analysis of covariance, Pearson correlations, and linear regressions. ResultsChildren with ADHD demonstrated a higher frequency of perseverative errors compared to TDC (p <.05), and their parents reported significantly more EF challenges (p <.001). No difference was observed in the working memory tasks. No significant volumetric differences were seen in the caudate or the putamen. A linear regression model suggested that the right caudate volume accounted for 10.3% of the variance in emotion regulation as reported by parents on the BRIEF-2 in the overall sample. DiscussionWe observed significant EF challenges without volumetric differences. However, the right caudate was correlated to parent ratings of emotional regulation, highlighting the need to consider emotional regulation difficulties in ADHD.