title: The effect of single-dose methylphenidate on resting-state network functional connectivity in ADHD.
abstract: We examined the effect of a single dose of methylphenidate (MPH) on whole brain functional connectivity, assessed using resting state functional MRI (rsfMRI), in young people with ADHD. 16 young people with ADHD participated in two rsfMRI scans in a randomized, placebo-controlled study with an acute dose of MPH (20 mg). 15 typically developing controls also performed the task under placebo conditions. The network-based statistic (NBS) was used to identify differential connectivity patterns between the MPH and placebo conditions in the ADHD group. Mean connectivity of the resulting sub-network was examined in the ADHD and control groups. Resting state functional connectivity (RSFC) analysis revealed significantly reduced connectivity under MPH compared to placebo in young people with ADHD. Findings were robust across a range of thresholds. No sub-networks of increased connectivity were found at any threshold. Mean connectivity of the identified sub-network was significantly higher in ADHD individuals in the placebo condition compared to controls, however there was no difference between MPH condition and controls. We demonstrated a significant MPH-related reduction in RSFC in a large, robust network primarily involving occipital, temporal and cerebellar regions, and visual, executive and default mode networks. These findings suggest that MPH is 'normalising' a higher RSFC in young people with ADHD. This study is a novel addition to the understanding of treatment effects on the brain in ADHD.
authors.affiliation: Developmental Imaging, Murdoch Childrens Research Institute, The Royal Children's Hospital, Melbourne, Australia. tim.silk@mcri.edu.au.|Department of Paediatrics, The University of Melbourne, Melbourne, Australia. tim.silk@mcri.edu.au.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Silk
authors.affiliation: Developmental Imaging, Murdoch Childrens Research Institute, The Royal Children's Hospital, Melbourne, Australia.
authors.forename: Charles
authors.initials: C
authors.lastname: Malpas
authors.affiliation: Academic Child Psychiatry Unit, Department of Paediatrics, The University of Melbourne, The Royal Children's Hospital, Melbourne, Australia.
authors.forename: Alasdair
authors.initials: A
authors.lastname: Vance
authors.affiliation: School of Psychological Sciences, Monash University, Melbourne, Australia.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Bellgrove
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000503:physiopathology; D001931:Brain Mapping; D000697:Central Nervous System Stimulants / Q000008:administration & dosage* / Q000009:adverse effects; D002648:Child; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage* / Q000009:adverse effects; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology; D009483:Neuropsychological Tests; D012146:Rest
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate
keywords: ADHD; Functional connectivity; MRI; Methylphenidate; Network based statistic