Attentional functions in children and adolescents with ADHD, depressive disorders, and the comorbid condition Thomas Gu ¨nther, 1 Kerstin Konrad, 1 Ste ´phane A. De Brito, 2 Beate Herpertz- Dahlmann, 3 and Timo D. Vloet 1,3 1 Child Neuropsychology Section, Department of Child and Adolescent Psychiatry, Medical Faculty, RWTH Aachen University, Germany; 2 Developmental Risk and Resilience Unit, Research Department of Clinical Educational and Health Psychology, Division of Psychology and Language Sciences, University College London, UK; 3 Department of Child and Adolescent Psychiatry, Medical Faculty, RWTH Aachen University, Germany Background: Attention-deficit hyperactivity disorder (ADHD) and depressive disorders (DDs) often co-occur in children and adolescents, but evidence on the respective influence of these disorders on attention parameters is inconsistent. This study examines the influence of DDs on ADHD in a model- oriented approach that includes selectivity and intensity attention parameters. Methods: Ten- to fif- teen-year-olds with ADHD (n = 63), DDs (n = 61), ADHD+DDs (n = 64), and healthy controls (n = 64) completed a battery of tests including five neuropsychological tasks (i.e., alertness, sustained attention, divided attention, go/no-go, and attentional set-shifting). Results: All clinical groups showed atten- tional problems, especially in more complex attentional tasks and in the intensity aspects of attention. We observed the most severe attentional impairments in children with ADHD that was independent from a comorbid DD. Conclusion: The clinical groups were significantly different from the healthy control group, especially in more complex attentional tasks and in the intensity aspects of attention. Some differences between ADHD, DDs and ADHD+DDs groups were detected on neuropsychological atten- tional performance, but the effects were not strong enough to differentiate the clinical groups from each other. Keywords: ADHD, depression, attention, neuropsychology. Children with attention-deficit hyperactivity disorder (ADHD) and children with depressive disorders (DDs) often have attention problems. Because both disorders have different therapeutic needs, a valid assessment of inattention with regard to the under- lying psychopathology is an essential clinical prob- lem. Moreover, these disorders co-occur in 15–75% of cases (for reviews see Biederman, Newcorn, & Sprich, 1991; Spencer et al., 2006) and the risk of suffering from DDs for children and adolescents with ADHD is 5.5 times higher than in children without ADHD (Angold, Costello, & Erkanli, 1999). In clinical practice, neuropsychological measure- ments frequently assess attention problems in chil- dren; however, while numerous studies have investigated children with pure ADHD (e.g., Goos, Crosbie, Payne, & Schachar, 2009), there is still a paucity of neuropsychological data on attention deficits associated with DDs. In addition, few neu- ropsychological studies have examined the influence of DDs on attentional performance in ADHD. In an early study, Seidman and co-workers (1995) indicated that measures of sustained attention, response inhibition, set-shifting, selective attention and memory in children with pure ADHD were sim- ilar to those with ADHD and comorbid disorders such as conduct disorder, anxiety disorders and DDs. Unfortunately, the sample sizes of the different groups were relatively small and the sample was not stratified by specific comorbid disorders. More recently, Favre et al. (2009) compared children with major depressive disorder and comorbid ADHD and focused on executive functioning, including aspects of attention. Although they found no significant dif- ferences, secondary power analyses revealed that a larger sample size would have identified a signifi- cantly reduced performance in visual attention and set-shifting in children with ADHD+DDs compared to children with only DDs. The available neuropsychological data comparing the attentional performance of children with DDs to healthy children have yielded mixed results. While some studies have not found differences in measures of sustained or selective attention (e.g., Calhoun & Dickerson Mayes, 2005; Mayes & Calhoun, 2007), others suggest that children with major depressive disorder have a reduced ability to maintain attention and show problems with set-shifting (Favre et al., 2009). Surprisingly, another study found that ado- lescents with major depression disorder made fewer errors and were more accurate in a go/no-go task compared to healthy adolescents (Kyte, Goodyer, & Sahakian, 2005). Thus, the current study compared the neuropsy- chological performance of children with ADHD, DDs alone, and ADHD+DDs to healthy controls (HC). Conflict of interest statement: No conflicts declared. Journal of Child Psychology and Psychiatry 52:3 (2011), pp 324–331 doi:10.1111/j.1469-7610.2010.02320.x Ó 2010 The Authors. Journal of Child Psychology and Psychiatry Ó 2010 Association for Child and Adolescent Mental Health. Published by Blackwell Publishing, 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main St, Malden, MA 02148, USA