Zhao-Min Wu1,2,3,4, Janita Bralten3,4, Li An1,2, Qing-Jiu Cao1,2, Xiao-Hua Cao1,2, Li Sun1,2, Lu Liu1,2, Li Yang1,2, Maarten Mennes4, Yu-Feng Zang5, Barbara Franke3,4,6, Martine Hoogman3,4, Yu-Feng Wang1,2. 1. 1 Peking University Sixth Hospital/Institute of Mental Health, National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China. 2. 2 Key Laboratory of Mental Health, Ministry of Health, Peking University, Beijing, China. 3. 3 Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands. 4. 4 Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands. 5. 5 Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China. 6. 6 Department of Psychiatry, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands.
Abstract
OBJECTIVE: Few studies have investigated verbal working memory-related functional connectivity patterns in participants with attention-deficit/hyperactivity disorder (ADHD). Thus, we aimed to compare working memory-related functional connectivity patterns in healthy children and those with ADHD, and study effects of methylphenidate (MPH). METHOD:Twenty-two boys with ADHD were scanned twice, under either MPH (single dose, 10 mg) or placebo, in a randomised, cross-over, counterbalanced placebo-controlled design. Thirty healthy boys were scanned once. We used fMRI during a numerical n-back task to examine functional connectivity patterns in case-control and MPH-placebo comparisons, using independent component analysis. RESULTS: There was no significant difference in behavioural performance between children with ADHD, treated with MPH or placebo, and healthy controls. Compared with controls, participants with ADHD under placebo showed increased functional connectivity within fronto-parietal and auditory networks, and decreased functional connectivity within the executive control network. MPH normalized the altered functional connectivity pattern and significantly enhanced functional connectivity within the executive control network, though in non-overlapping areas. CONCLUSION: Our study contributes to the identification of the neural substrates of working memory. Single dose of MPH normalized the altered brain functional connectivity network, but had no enhancing effect on (non-impaired) behavioural performance.
RCT Entities:
OBJECTIVE: Few studies have investigated verbal working memory-related functional connectivity patterns in participants with attention-deficit/hyperactivity disorder (ADHD). Thus, we aimed to compare working memory-related functional connectivity patterns in healthy children and those with ADHD, and study effects of methylphenidate (MPH). METHOD: Twenty-two boys with ADHD were scanned twice, under either MPH (single dose, 10 mg) or placebo, in a randomised, cross-over, counterbalanced placebo-controlled design. Thirty healthy boys were scanned once. We used fMRI during a numerical n-back task to examine functional connectivity patterns in case-control and MPH-placebo comparisons, using independent component analysis. RESULTS: There was no significant difference in behavioural performance between children with ADHD, treated with MPH or placebo, and healthy controls. Compared with controls, participants with ADHD under placebo showed increased functional connectivity within fronto-parietal and auditory networks, and decreased functional connectivity within the executive control network. MPH normalized the altered functional connectivity pattern and significantly enhanced functional connectivity within the executive control network, though in non-overlapping areas. CONCLUSION: Our study contributes to the identification of the neural substrates of working memory. Single dose of MPH normalized the altered brain functional connectivity network, but had no enhancing effect on (non-impaired) behavioural performance.
Entities:
Keywords:
ADHD; functional connectivity; methylphenidate; verbal working memory