title: Altered functional brain connectivity in a non-clinical sample of young adults with attention-deficit/hyperactivity disorder.
abstract: Attention-deficit/hyperactivity disorder (ADHD) is characterized by symptoms of inattention and hyperactivity/impulsivity that often persist in adulthood. There is a growing consensus that ADHD is associated with abnormal function of diffuse brain networks, but such alterations remain poorly characterized. Using resting-state functional magnetic resonance imaging, we characterized multivariate (complex network measures), bivariate (network-based statistic), and univariate (regional homogeneity) properties of brain networks in a non-clinical, drug-naive sample of high-functioning young men and women with ADHD (nine males, seven females) and a group of matched healthy controls. Data from our sample allowed the isolation of intrinsic functional connectivity alterations specific to ADHD diagnosis and symptoms that are not related to developmental delays, general cognitive dysfunction, or history of medication use. Multivariate results suggested that frontal, temporal, and occipital cortices were abnormally connected locally as well as with the rest of the brain in individuals with ADHD. Results from the network-based statistic support and extend multivariate results by isolating two brain networks comprising regions between which inter-regional connectivity was significantly altered in the ADHD group; namely, a frontal amygdala-occipital network and a frontal temporal-occipital network. Brain behavior correlations further highlighted the key role of altered orbitofrontal-temporal and frontal-amygdala connectivity for symptoms of inattention and hyperactivity/impulsivity. All univariate properties were similar between groups. Taken together, results from this study show that the diagnosis and the two main symptom dimensions of ADHD are related to altered intrinsic connectivity in orbitofrontal-temporal-occipital and fronto-amygdala-occipital networks. Accordingly, our findings highlight the importance of extending the conceptualization of ADHD beyond segregated fronto-striatal alterations.
authors.affiliation: Queensland Brain Institute, The University of Queensland, St Lucia, Queensland 4072, Australia. l.cocchi@uq.edu.au
authors.forename: Luca
authors.initials: L
authors.lastname: Cocchi
authors.forename: Ivanei E
authors.initials: IE
authors.lastname: Bramati
authors.forename: Andrew
authors.initials: A
authors.lastname: Zalesky
authors.forename: Emi
authors.initials: E
authors.lastname: Furukawa
authors.forename: Leonardo F
authors.initials: LF
authors.lastname: Fontenelle
authors.forename: Jorge
authors.initials: J
authors.lastname: Moll
authors.forename: Gail
authors.initials: G
authors.lastname: Tripp
authors.forename: Paulo
authors.initials: P
authors.lastname: Mattos
mesh_terms: D000328:Adult; D000679:Amygdala / Q000503:physiopathology*; D001288:Attention / Q000502:physiology; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000503:physiopathology*; D005260:Female; D059907:Functional Neuroimaging / Q000379:methods / Q000523:psychology*; D006801:Humans; D007175:Impulsive Behavior / Q000150:complications / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000523:psychology; D008297:Male; D009434:Neural Pathways / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D057566:Self Report