Over the past century, the syndrome currently referred to as attention-deficit/hyperactivity disorder (ADHD) has been conceptualized in relation to varying cognitive problems including attention, reward response, executive functioning, and other cognitive processes.1 More recently, it has become clear that whereas ADHD is associated at the group level with a range of cognitive impairments, no single cognitive dysfunction characterizes all children with ADHD.2,3 In other words, ADHD is not a one-size-fits-all phenomenon. Patients with this syndrome do not fit into any one category and present with widely differing co-occurring disorders—including varying cognitive profiles.
Thus, ADHD represents not a single disease entity but a heterogeneous group of patients who require differentiated analysis, assessment, and treatment. This article focuses on the cognitive presentation of children (and, to a lesser extent, adults) with ADHD.
DSM-IV specifies that there are 3 subtypes of ADHD:
• Primarily inattentive
• Primarily hyperactive-impulsive
• Combined inattentive and hyperactive-impulsive
Much research has attempted to map particular cognitive problems to particular DSM-IV subtypes but, to date, there has been no consensus. Contemporary neuroscience has helped clarify that cognition and affect are closely related—cognitive computations depend heavily on emotional arousal and valence, just as affective response depends in part on cognitive evaluation.4
The diagnosis of ADHD is not based on cognitive difficulties but rather on evaluation of hallmark behaviors using standardized, nationally validated rating scales as well as a structured clinical interview with the caregiver.5 Cognitive impairments constitute secondary features that often accompany the disorder and need to be considered as part of a comprehensive clinical formulation and multidisciplinary treatment plan. If a child’s cognitive profile is not considered, he or she may respond positively on behavioral ratings to standard treatment (eg, a psychostimulant medication), yet still fail to attain his best academic or social functioning ability because of cognitive impairment.
Cognitive problems and clinical options
The 10 well-established cognitive problems listed in Table 1 should be salient for psychiatric care of ADHD.2 They fall into 2 broad groups: comorbid syndromes and ADHD-related cognitive problems, which are characterized by context-dependent response profiles. These problems are organized by illustrative clinical presentation in Table 2.
It is unknown whether any of the context-dependent cognitive problems are unique to ADHD. However, all appear to be at least partially specific to ADHD because they are not explained by co-occurring psychiatric, behavioral, or learning problems and, in most instances, they are more clearly associated with ADHD (larger effect sizes) than with other disorders.6 Thus, they are part of the established correlates of ADHD at the group level.
1. Barkley RA. Behavioral inhibition, sustained attention, and executive functions: constructing a unifying theory of ADHD. Psychol Bull.1997;121:65-94.
2. Nigg JT. Neuropsychological theory and findings in attention-deficit/hyperactivity disorder: the state of the field and salient challenges for the coming decade. Biol Psychiatry. 2005;57:1424-1435.
3. Nigg JT, Willcutt EG, Doyle AE, Sonuga-Barke EJ. Causal heterogeneity in attention-deficit/hyperactivity disorder: do we need neuropsychologically impaired subtypes? Biol Psychiatry. 2005;57:1224-1230.
4. Nigg JT, Casey BJ. An integrative theory of attention-deficit/hyperactivity disorder based on the cognitive and affective neurosciences. Dev Psychopathol. 2005;17:785-806.
5. Pelham WE Jr, Fabiano GA. Evidence-based psychosocial treatments for attention-deficit/hyperactivity disorder. J Clin Child Adolesc Psychol. 2008;37: 184-214.
6. Willcutt E, Sonuga-Barke E, Nigg JT, Sergeant JA. Neuropsychology of childhood disorders. In: Banaschewski T, Rohde LA, eds. Biological Child Psychiatry: Recent Trends and Developments. Advances in Biological Psychiatry, Vol 24. Basel: Karger; 2008:195-226.
7. Jepsen JR, Fagerlund B, Mortensen EL. Do attention deficits influence IQ assessment in children and adolescents with ADHD? J Atten Disord. 2008 Sep 24; [Epub ahead of print].
8. Hinshaw SP. Externalizing behavior problems and academic underachievement in childhood and adolescence: causal relationships and underlying mechanisms. Psychol Bull. 1992;111:127-155.
9. Rayner K, Foorman BR, Perfetti CA, et al. How psychological science informs the teaching of reading. Psychol Sci. 2001;2(suppl 2):31-74.
10. Eskritt M, McLeod K. Children’s note taking as a mnemonic tool. J Exp Child Psychol. 2008;101:52-74.
11. Drummond CR, Ahmad SA, Rourke BP. Rules for the classification of younger children with nonverbal learning disabilities and basic phonological processing disabilities. Arch Clin Neuropsychol. 2005;20:171-182.
12. Rourke BP, Ahmad SA, Collins DW, et al. Child clinical/pediatric neuropsychology: some recent advances. Annu Rev Psychol. 2002;53:309-339.
13. Meltzer L. Executive Function in Education: From Theory to Practice. New York: Guilford Press; 2007.
14. Diamond A. Close interrelation of motor development and cognitive development and of the cerebellum and prefrontal cortex. Child Dev. 2000;71:44-56.
15. Eliasson AC, Rösblad B, Forssberg H. Disturbances in programming goal-directed arm movements in children with ADHD. Dev Med Child Neurol. 2004;46: 19-27.
16. Gillberg C. Deficits in attention, motor control, and perception: a brief review. Arch Dis Child.2003;88: 904-910.
17. Huang-Pollock CL, Nigg JT. Searching for the attention deficit in attention deficit hyperactivity disorder: the case of visuospatial orienting. Clin Psychol Rev. 2003;23:801-830.
18. Huang-Pollock CL, Nigg JT, Carr TH. Deficient attention is hard to find: applying the perceptual load model of selective attention to attention deficit hyperactivity disorder subtypes. J Child Psychol Psychiatry. 2005;46:1211-1218.
19. Barry RJ, Clarke AR, Johnstone SJ. A review of electrophysiology in attention-deficit/hyperactivity disorder, I: qualitative and quantitative electroencephalography. Clin Neurophysiol. 2003;114:171-183.
20. Walters AS, Silvestri R, Zucconi M, et al. Review of the possible relationship and hypothetical links between attention deficit hyperactivity disorder (ADHD) and the simple sleep related movement disorders, parasomnias, hypersomnias, and circadian rhythm disorders. J Clin Sleep Med. 2008;15:591-600.
21. Chervin RD, Ruzicka DL, Giordani BJ, et al. Sleep disordered breathing, behavior, and cognition in children before and after adenotonsillectomy. Pediatrics. 2006;117:e769-e778.
22. Tomporowski PD. Effects of acute bouts of exercise on cognition. Acta Psychol (Amst). 2003;112: 297-324.
23. Castelli DM, Hillman CH, Buck SM, Erwin HE. Physical fitness and academic achievement in third- and fifth-grade students. J Sport Exerc Psychol. 2007;29:239-252.
24. Budde H, Voelcker-Rehage C, Pietrabyk-Kendziorra S, et al. Acute coordinative exercise improves attentional performance in adolescents. Neurosci Lett. 2008;441:219-223.
25. Wigal SB, Nemet D, Swanson JM, et al. Catecholamine response to exercise in children with attention deficit hyperactivity disorder. Pediatr Res. 2003;53:756-761.
26. Fanjiang G, Kleinman RE. Nutrition and performance in children. Curr Opin Clin Nutr Metab Care. 2007;10:342-347.
27. Luman M, Oosterlaan J, Sergeant JA. The impact of reinforcement contingencies on AD/HD: a review and theoretical appraisal [published correction appears in Clin Psychol Rev. 2005;25:533]. Clin Psychol Rev. 2005;25:183-213.
28. Toplak ME, Rucklidge JJ, Hetherington R, et al. Time perception deficits in attention-deficit/hyperactivity disorder and comorbid reading difficulties in child and adolescent samples. J Child Psychol Psychiatry. 2003;44:888-903.
29. Martinussen R, Hayden J, Hogg-Johnson S, Tannock R. A meta-analysis of working memory impairments in children with attention-deficit/hyperactivity disorder. J Am Acad Child Adolesc Psychiatry. 2005; 44:377-384.
30. Strauss E, Sherman EMS, Spreen O. A Compendium of Neuropsychological Tests: Administration, Norms, Commentary. 3rd ed. New York: Oxford University Press; 2006.
31. Sohlberg MM, Mateer CA. Improving attention and managing attentional problems: adapting rehabilitation techniques to adults with ADHD. In: Wasserstein J, Wolf L, LeFever FF, eds. Adult Attention Deficit Disorder: Brain Mechanisms and Life Outcomes. Annals of the New York Academy of Sciences, Vol 931. New York: New York Academy of Sciences; 2001:359-375.
32. Thorell LB, Lindqvist S, Bergman Nutley S, et al. Training and transfer effects of executive functions in preschool children. Dev Sci. 2009;12:106-113.
33. Iglowstein I, Jenni OG, Molinari L, Largo RH. Sleep duration from infancy to adolescence: reference values and generational trends. Pediatrics. 2003;111: 302-307.
34. Gidding SS, Dennison BA, Birch LL, et al. Dietary recommendations for children and adolescents: a guide for practitioners: consensus statement from the American Heart Association [published correction appears in Circulation.2005;112:2375]. Circulation. 2005;112:2061-2075.
35. KidsHealth. http://kidshealth.org/parent/nutrition_fit/fitness/exercise.html. Accessed February 9, 2009.
Chervin RD, Ruzicka DL, Giordani BJ, et al. Sleep disordered breathing, behavior, and cognition in children before and after adenotonsillectomy. Pediatrics. 2006;117:e769-e778.
Pelham WE Jr, Fabiano GA. Evidence-based psychosocial treatments for attention-deficit/hyperactivity disorder. J Clin Child Adolesc Psychol. 2008;37: 184-214.