Neural mechanisms of response inhibition and impulsivity in 22q11.2 deletion carriers and idiopathic attention deficit hyperactivity disorder

Abstract

•22q11DS offers a compelling model to understand the neural substrates of attentional dysfunction.•First study directly comparing neural function in 22q11DS vs. ADHD patients•22q11DS and ADHD patients show a shared deficit in RI-related activation.•ADHD patients showed greater activity in the middle frontal gyrus than 22q11DS during RI.•Neural activity is inversely correlated with self-reported Cognitive Impulsivity in 22q11DS.

Fig. 1

Neural activity during successful RI (Stop-Successful vs. Go contrast): 22q11DS and ADHD participants versus controls. (a) Green clusters represent activity from the contrast of controls > 22q11DS, and dark blue clusters represent activity from the contrast of controls > ADHD. (b) Red colors represent regions showing a conjunction of neural activity from the contrasts of controls > 22q11DS and controls > ADHD.

Fig. 2

Conjunction analysis showing significant differences in RI-related neural activity common to 22q11DS and ADHD patients compared to controls. Nine anatomically-defined ROIs were intersected with the conjunction group map to extract percent signal change. The X-axis represents the group (controls = gray, ADHD patients = dotted, 22q11DS = black) and the Y-axis represents percent signal change.

Fig. 3

Neural activity differences for successful stopping: 22q11DS versus ADHD. Turquoise maps represent activity from the contrast of Stop Successful–Go, ADHD > 22q11DS, to investigate differences in activity related to response inhibition. Brain orientations are labeled such that S = superior, I = inferior, P = posterior, and A = anterior; R = right and L = left.

Fig. 4

Relationship between RI-related neural activity and trait impulsivity in 22q11DS and ADHD patients. Activity maps display regions that showed a significant relationship between Stop Successful–Go activity and trait impulsivity values, using the following color scheme: turquoise = ADHD > 22q11DS, yellow = 22q11DS alone, and magenta = 22q11DS > ADHD. No regions showed a significant correlation within ADHD alone. Brain orientations are labeled such that S = superior, I = inferior, P = posterior, and A = anterior; R = right and L = left. The X-axis values represent the (a) Cognitive Impulsivity subscore or (b) Behavioral Impulsivity subscore of the Barratt Impulsivity Scale, and the Y-axis values represent the percent signal change during Stop Successful–Go (with age and years of education included in the analysis as covariates of non-interest). Higher scores on cognitive or Behavioral Impulsivity scales indicate higher levels of trait impulsivity. ADHD patient data are shown as open circles, 22q11DS patient data are shown as black squares, the ADHD trend line is shown as a dashed line, and the 22q11DS trend line is shown as a solid line.