Cognitive control in adults with attention-deficit/hyperactivity disorder Margaretha Dramsdahl a,b, ⁎, René Westerhausen c , Jan Haavik a,d,e , Kenneth Hugdahl a,c,e , Kerstin J. Plessen e,f,g a Division of Psychiatry, Haukeland University Hospital, Bergen, Norway b Department of Clinical Medicine, Faculty of Medicine and Dentistry, University of Bergen, Norway c Department of Biological and Medical Psychology, University of Bergen, Norway d Department of Biomedicine, Faculty of Medicine and Dentistry, University of Bergen, Norway e K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Norway f Center for Child and Adolescent Psychiatry, Bispebjerg Hospital Copenhagen, Denmark g Institute for Neurology, Psychiatry, and Sensory Sciences, University of Copenhagen, Denmark abstract article info Article history: Received 21 April 2010 Received in revised form 28 March 2011 Accepted 12 April 2011 Keywords: ADHD Dichotic listening Cognitive processes Executive functions Attentional networks The objective of the present study was to investigate the ability of adults with Attention-Deficit/Hyperactivity Disorder (ADHD) to direct their attention and exert cognitive control in a forced instruction dichotic listening (DL) task. The performance of 29 adults with ADHD was compared with 58 matched controls from the Bergen Dichotic Listening Database (N N 1500). Participants in the Bergen DL task listen to and report from conflicting consonant–vowel combinations (two different syllables presented simultaneously, one to each ear). They are asked to report the syllable they hear (non-forced condition), or to focus and report either the right- or left- ear syllable (forced-right and forced-left condition). This procedure is presumed to tap distinct cognitive processes: perception (non-forced condition), orienting of attention (forced-right condition), and cognitive control (forced-left condition). Adults with ADHD did not show significant impairment in the conditions tapping perception and attention orientation, but were significantly impaired in their ability to report the left- ear syllable during the forced-left instruction condition, whereas the control group showed the expected left- ear advantage in this condition. This supports the hypothesis of a deficit in cognitive control in the ADHD group, presumably mediated by a deficit in a prefrontal neuronal circuitry. Our results may have implications for psychosocial adjustment for persons with ADHD in educational and work environments. © 2011 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Attention-Deficit/Hyperactivity Disorder (ADHD) is a disorder with three different clinical subtypes grouped according to their dominant symptoms; the inattentive, the hyperactive/impulsive, and the combined type (American Psychiatric Association, 2000). The estimated worldwide-pooled prevalence in children and adolescents with ADHD is 5.3% (Polanczyk et al., 2007). Although ADHD is primarily diagnosed in childhood the majority of children affected shows persistent symptoms which cause severe functional impair- ment into adulthood (Biederman and Faraone, 2005; Faraone et al., 2006). Typical symptoms that interfere with daily life are difficulties to maintain attention-span during longer periods of time or to keep attention focused despite distractions, problems in following in- structions and to complete activities that demand cognitive focus. Several causal models have been presented that attempt to explain the symptoms of ADHD (e.g. Sergeant et al., 2003; Nigg, 2006). Earlier models have stressed the dysfunction in a few core domains, such as problems with impaired executive functions (EF) and response inhibition (Pennington and Ozonoff, 1996; Barkley, 1997). ADHD is, however, likely to be a neuropsychologically heterogeneous disorder (Nigg and Casey, 2005; Willcutt et al., 2005; Doyle, 2006; Sonuga- Barke et al., 2010), reflected by the recently described multiple pathways models (Sergeant et al., 2003; Sonuga-Barke, 2005; Castellanos et al., 2006), which highlight other domains than merely EF as problematic, e.g. state regulation (Sanders, 1983; Sergeant, 2005) or delay aversion (Sonuga-Barke et al., 1992). Deficits in EF or in cognitive control are, however, considered key impairments in ADHD in most of the existing models. Although not exclusive (Jurado and Rosselli, 2007), cognitive abilities often included into the concept of EF are working memory, response inhibition, set-shifting, planning and fluency (Pennington and Ozonoff, 1996; Sergeant et al., 2003). We will in the following use EF and cognitive control as synonym concepts, both defined by the ability to cope with disturbances and conflict situations, where bottom-up, automatic Psychiatry Research 188 (2011) 406–410 ⁎ Corresponding author at: Division of Psychiatry, Haukeland University Hospital, Jonas Liesvei 65, N-5021 Bergen, Norway. Tel.: + 47 958354; fax: + 47 55975146. E-mail address: margaretha.dramsdahl@helse-bergen.no (M. Dramsdahl). 0165-1781/$ – see front matter © 2011 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.psychres.2011.04.014 Contents lists available at ScienceDirect Psychiatry Research journal homepage: www.elsevier.com/locate/psychres