Statistical Parametric Map (SPM) showing foci of significant interactions between diagnosis and gender (overlaid on a mean structural scan from the 60 participants and thresholded at p < .001 uncorrected), with groups’ mean grey matter volume parameter estimate (age regressed out, standard-error displayed) within our significant cluster in the ACC (MNI coordinates: x = 3; y = 35; z = 4) (TD Boys, n = 13; TD Girls, n = 14; Boys with ADHD, n = 18; Girls with ADHD, n = 15). Abbreviations: ACC, anterior cingulate cortex; ADHD, attention-deficit/hyperactivity disorder; GM, grey matter; TD, typically developing.