title: Diminished prefrontal oxygenation with normal and above-average verbal fluency performance in adult ADHD.
abstract: Attention-Deficit/Hyperactivity Disorder (ADHD) in adults is associated with deficits in executive functions such as verbal fluency. Functional near-infrared spectroscopy offers the possibility to measure brain activity during verbal fluency in psychiatric patients due to low susceptibility to movements artefacts. Fourteen patients with mainly combined ADHD subtype and 14 healthy controls matched for age, gender, handedness, education level, and intelligence showed equal performance in phonological verbal fluency and higher performance in semantical verbal fluency in comparison to the controls. On the level of brain function indicated by concentration changes of oxygenated and deoxygenated haemoglobin, both groups showed inferior frontal brain activity during both tasks. ADHD patients had a lower magnitude of oxygenation and a significant negative correlation of brain activity with performance, i.e. higher brain activity was associated with lower performance. These results might be interpreted as a lack of disease related deficits, as an economical recruitment of cognitive resources, or - more likely - as an expression of a benefit in the patient group. High verbal competence in our samples could contribute to these findings. One speculative and post hoc explanation aims at the clinically well-known phenomenon of hyperfocusing in patients with ADHD.
authors.affiliation: University of Wuerzburg, Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital Wuerzburg, Fuechsleinstrasse 15, 97080 Wuerzburg, Germany. schecklman_m@klinik.uni-wuerzburg.de
authors.forename: Martin
authors.initials: M
authors.lastname: Schecklmann
authors.forename: Ann-Christine
authors.initials: AC
authors.lastname: Ehlis
authors.forename: Michael M
authors.initials: MM
authors.lastname: Plichta
authors.forename: Jasmin
authors.initials: J
authors.lastname: Romanos
authors.forename: Monika
authors.initials: M
authors.lastname: Heine
authors.forename: Andrea
authors.initials: A
authors.lastname: Boreatti-Hümmer
authors.forename: Christian
authors.initials: C
authors.lastname: Jacob
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Fallgatter
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000378:metabolism*; D001931:Brain Mapping / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D010700:Phonetics; D017397:Prefrontal Cortex / Q000378:metabolism*; D012660:Semantics; D019265:Spectroscopy, Near-Infrared / Q000379:methods; D013065:Speech Intelligibility / Q000502:physiology*; D013647:Task Performance and Analysis