BACKGROUND: A lack of inhibitory control has been suggested to be the core deficit in children with attention deficit hyperactivity disorder (ADHD). This means that a primary deficit in behavioral inhibition mediates a cascade of secondary deficits in other executive functions, such as arousal regulation. Clinical observations have revealed that with increasing age symptoms of hyperactivity and impulsivity decline at a higher rate than those of inattention. This might imply that a deficit in attention rather than a lack of inhibitory control is the major feature in adult ADHD. METHOD: To study whether an attentional or inhibitory deficit predominates, the stop-signal task and the stop-change task were presented to 24 adults with ADHD combined subtype and 24 controls. RESULTS: Relative to controls, the stop-signal reaction time (SSRT) was significantly more prolonged than the go-stimulus reaction time (RT) in patients with ADHD. This disproportionate elongation of the SSRT was comparable across tasks, even though the stop-change task exerted more complex (or at least different) demands on the inhibitory system than the stop-signal task. ADHD patients had a higher proportion of choice errors, possibly reflecting more premature responses. Specifically in the stop-change task, patients had more variable choice responses and made more inappropriate change responses, which may also reflect enhanced impulsivity. CONCLUSIONS: The results support a core deficit in behavioral inhibition in adults with ADHD. We further suggest that there is more evidence for a critical role of deficient inhibitory control in adults than in children with ADHD.
BACKGROUND: A lack of inhibitory control has been suggested to be the core deficit in children with attention deficit hyperactivity disorder (ADHD). This means that a primary deficit in behavioral inhibition mediates a cascade of secondary deficits in other executive functions, such as arousal regulation. Clinical observations have revealed that with increasing age symptoms of hyperactivity and impulsivity decline at a higher rate than those of inattention. This might imply that a deficit in attention rather than a lack of inhibitory control is the major feature in adult ADHD. METHOD: To study whether an attentional or inhibitory deficit predominates, the stop-signal task and the stop-change task were presented to 24 adults with ADHD combined subtype and 24 controls. RESULTS: Relative to controls, the stop-signal reaction time (SSRT) was significantly more prolonged than the go-stimulus reaction time (RT) in patients with ADHD. This disproportionate elongation of the SSRT was comparable across tasks, even though the stop-change task exerted more complex (or at least different) demands on the inhibitory system than the stop-signal task. ADHDpatients had a higher proportion of choice errors, possibly reflecting more premature responses. Specifically in the stop-change task, patients had more variable choice responses and made more inappropriate change responses, which may also reflect enhanced impulsivity. CONCLUSIONS: The results support a core deficit in behavioral inhibition in adults with ADHD. We further suggest that there is more evidence for a critical role of deficient inhibitory control in adults than in children with ADHD.
Authors: Richard C Mulligan; Valerie S Knopik; Lawrence H Sweet; Mariellen Fischer; Michael Seidenberg; Stephen M Rao Journal: Psychiatry Res Date: 2011-09-21 Impact factor: 3.222
Authors: H N Alexander Logemann; Koen B E Böcker; Peter K H Deschamps; Peter N van Harten; Jeroen Koning; Chantal Kemner; Zsófia Logemann-Molnár; J Leon Kenemans Journal: Psychopharmacology (Berl) Date: 2016-10-17 Impact factor: 4.530
Authors: Sandra J J Kooij; Susanne Bejerot; Andrew Blackwell; Herve Caci; Miquel Casas-Brugué; Pieter J Carpentier; Dan Edvinsson; John Fayyad; Karin Foeken; Michael Fitzgerald; Veronique Gaillac; Ylva Ginsberg; Chantal Henry; Johanna Krause; Michael B Lensing; Iris Manor; Helmut Niederhofer; Carlos Nunes-Filipe; Martin D Ohlmeier; Pierre Oswald; Stefano Pallanti; Artemios Pehlivanidis; Josep A Ramos-Quiroga; Maria Rastam; Doris Ryffel-Rawak; Steven Stes; Philip Asherson Journal: BMC Psychiatry Date: 2010-09-03 Impact factor: 3.630