The following is an abstract of the presentation of Rosemary Tannock, Ph.D. on cognitive and behavioral correlates to AD/HD. The abstract is designed for the use of panelists and participants in the conference and as a reference document for anyone interested in the conference deliberations. We are grateful to the author for summarizing her materials and making them available in a timely fashion. (Graphics and tables version available for easier reading)

Neuropsychological correlates provide useful criteria for examining the validity of attention deficit hyperactivity disorder (ADHD), because they do not share method variance with clinical measures used to assess psychiatric symptomatology. Performance is assessed directly and is not subject to confounding factors such as recall bias or halo effects. Also, these data provide insights into the neural substrates of the disorder (Halperin, McKay, 1998; Lezak, 1995).

A systematic review of the literature was undertaken using Medline and Psychlit bibliography databases and covering the following correlates: (1) general intellectual function, (2) academic achievement, (3) neuropsychological function (motor function, perception, visual-motor integration, language, memory, executive functions), and (4) cognitive processes (alerting, orienting, executive control). The following questions were addressed: (1) What are the impairments/strengths associated with ADHD? (2) Do these impairments/strengths vary by gender and/or by age? (3) Are these impairments/strengths influenced by the presence of concurrent disorders? (4) Are these impairments/strengths specific to ADHD? and (5) What neural networks are implicated?

General Intellectual Function

Intelligence tests provide a broad index of higher cortical functioning that can be used to generate hypotheses for further investigation using neuropsychological and experimental cognitive techniques. Their psychometric properties remain robust for the clinical group of ADHD (Schwean, Saklofske, 1998). Compared with normative data, ADHD is associated typically with lower full-scale IQ and subtest scores (particularly those comprising an index of working memory), but the mean levels of intellectual functioning are well within the normal range. These findings are robust across age (preschool through adulthood), gender (although girls may exhibit greater intellectual impairment), study design (cross-sectional, longitudinal) or source of sample (epidemiological, pediatric, or psychiatric clinic), and various test versions (Saklofske, Schwean, Yackalic, et al., 1994; Sonuga-Barke, Lamparelli, Stevenson, et al., 1994; Mariani, Barkley, 1997; McGee, Williams, Moffit, et al., 1989; Barkley, DuPaul, McMurray, 1990; Biederman, Faraone, Taylor, et al., 1998; Seidman, Biederman, Faraone, et al., 1997; Seidman, Biederman, Faraone, et al., 1997; Gaub, Carlson, 1997). Also, they generally hold for studies that have controlled for the presence of comorbid disorders (Faraone, Biederman, Lehman, et al.,1993; Faraone, Biederman, Weber, et al., 1998; Newby, Recht, Caldwell, et al., 1993). By contrast, the findings do not appear to hold for the predominantly hyperactive subtype of ADHD, suggesting that the intellectual profile may be a correlate of inattention rather than hyperactivity/impulsiveness (Gaub, Carlson, 1997; Semrud-Clikeman, Biederman, Sprich, et al., 1992; Hinshaw, 1992; Barkley, Anastopoulos, Guevremont, et al., 1991). Preliminary evidence that male (but not female) siblings of children with ADHD exhibit a similar intellectual profile supports the hypothesis that ADHD is familial (Faraone, Biederman, Lehman, et al., 1993). This intellectual profile is not specific to ADHD; it is also associated with learning disabilities and other disruptive behavior disorders (Newby, Recht, Caldwell, et al., 1993). Thus, intellectual correlates of ADHD may have conceptual but not diagnostic significance.

Academic Achievement

Academic achievement tests provide a more detailed profile of strengths and weaknesses in underlying component skills that contribute to academic competency and indicate the presence of a learning disability. One of the most robust findings is a higher rate of school failure (Semrud-Clikeman, Biederman, Sprich, et al., 1992; Hinshaw, 1992; Barkley, Anastopoulos, Guevremont, et al., 1991). This is evidenced most clearly by low productivity but also by lower scores (on average, 0.5 S.D. lower) on reading (decoding, comprehension), spelling, and arithmetic, and elevated rates of grade repetition, learning disabilities, remedial tutoring, and special class placement, despite average levels of intellectual functioning. Academic underachievement is evident in both girls and boys as well as siblings, it occurs in preschool years and endures through adolescence (Barkley, DuPaul, McMurray, 1990; Faraone, Biederman, Lehman, et al., 1993; Faraone, Biederman, Weber, et al., 1998; Zentall, 1990). It is a correlate of ADHD per se and cannot be accounted for by psychiatric comorbidity (which tends to influence school placement rather than school failure or intellectual ability) or comorbid learning disabilities (Faraone, Biederman, Lehman, et al., 1993; Faraone, Biederman, Weber, et al., 1998). However, academic problems, particularly in arithmetic, are more common among predominantly inattentive and combined subtypes of ADHD, suggesting that these problems are related to inattention rather than hyperactivity/impulsivity (Hynd, Lorys, Semrud-Clikeman, et al., 1991; Baumgaertel, Wolraich, Dietrich, 1995; Lahey, Applegate, McBurnett, et al., 1994; Gaub, Carlson, 1997; Lamminm @ ki, Ahonen, N @ rhi, et al., 1995; Marshall, Hynd, Handwerk, et al., 1997. The nature of the academic impairments (particularly in individuals without comorbid learning disabilities) suggests problems in effortful processing. However, there is no evidence of a profile that is uniquely associated with ADHD.

Neuropsychological Function

Neuropsychological tests provide a detailed assessment of a wide array of cognitive functions that afford insights into brain-behavior relationships; they are sensitive to subtle deficits that interfere with learning and achievement. The most consistent (albeit not invariable) findings are impairments in “executive functions,” an umbrella term denoting a range of higher order, effortful, self-regulatory functions whose formal definition and measurement (particularly in children) remain elusive and under debate (Pennington, 1997; Tannock, 1998; Pennington, Ozonoff, 1996). However, impairments in component functions, particularly those associated with control of motor responses (planning, inhibition) and working memory, are clearly evident during effortful tasks in preschoolers, children, and adolescents, using a variety of measures requiring both fast or slow processing of information (Mariani, Barkley, 1997; Seidman, Biederman, Faraone, et al., 1997; Seidman, Biederman, Faraone, et al., 1997; Pennington, Ozonoff, 1996; Nigg, Hinshaw, Carte, et al., in press; Seidman, Biederman, Faraone, et al.,1995). These findings generally hold after controlling for comorbid psychiatric disorders and learning disabilities (Nigg, Hinshaw, Carte, et al., in press; Seidman, Biederman, Faraone, et al., 1995). Motor planning and inhibition problems are not typically associated with learning disabilities, although a combination of impairments in motor control, perception, speech-language, and attention is discernible in some children (Gillberg, Rasmussen, Carlstrom, et al., 1982; Hellgren, Gillberg, Bagenholm, et al., 1994). Reciprocally, verbal impairments associated with reading disabilities (phonological processing, verbal memory) are not associated with ADHD (Javorsky, 1996; Felton, Wood, 1989). Moreover, verbal impairments reflecting difficulties in use of language for organization of information and self-regulation (language-mediated processing) are more strongly associated with ADHD than with learning disabilities (Tannock, Schachar, 1996). These patterns of findings indicate at least some neuropsychological differentiation between these overlapping disorders. On the other hand, evidence of impairments in many component functions (including motor inhibition) in a wide range of clinical populations mitigates specificity for ADHD (Gold, Carpenter, Randolph, et al., 1997; Matier-Sharma, Perachio, Newcorn, 1995; Purcell, Maruff, Hyrios, et al., 1998).

Information Processing

Methods derived from information processing theory allow decomposition and more precise measurement (latency and accuracy) of the complex web of cognitive processes involved in most neuropsychological measures (Cohen, 1993). The most robust finding is of slow, variable, and inaccurate response latencies across a range of different measures, implicating impairments in energetic state regulation, preparation, maintenance, and inhibition or adjustment of motor control processes. Three component processing systems are implicated: sustained attention or vigilance, which refers to a state of readiness to respond (CPT paradigms) (Losier, McGrath, Klein, 1996; Corkum, Seigel, 1993; Van der Meere, 1996; Sergeant, Van der Meere, 1990), selective attention or spatial allocation of attention (visuospatial orienting paradigms) (Nigg, Swanson, Hinshaw, 1997; Pearson, Yaffee, Loveland, et al., 1995; Swanson, Posner, Potkin, et al., 1991; Tannock, Schachar, Logan, 1993), and response inhibition (stop-signal, delay-aversion paradigms) (Sonuga-Barke, Taylor, Hepenstall, 1992; Sonuga-Barke, Williams, Hall, et al., 1996; Oosterlaan, Logan, Sergeant, 1998; Schachar, Logan, 1990; Schachar, Tannock, Marriott, et al., 1995). The findings are not incontrovertible. For example, impairments in sustained attention are evident across the lifespan (preschool through adulthood) regardless of comorbidity, but findings are influenced strongly by temporal parameters (interstimulus interval, trial length, etc.), stimulus modality, memory load, and context (presence/absence of experimenter, rewards) (Purcell, Maruff, Hyrios, et al., 1998; Cohen, 1993; Van der Meere, 1996; Sergeant, Van der Meere, 1990; Halperin, Wolf, Greenblatt, et al., 1991b; Chee, Logan, Schachar, et al., 1989). In general, ADHD is associated with inefficient performance (slow, inaccurate) and vigilance decrements (faster than normal decline in performance) that occur with increased demand for effortful processing (Van der Meere, 1996; Sergeant, Van der Meere, 1990). However, performance impairments on vigilance tasks are exhibited by a wide range of clinical populations, once again challenging the notion of specificity for ADHD per se. Dysfunction of the visuospatial orienting system (particularly in the right hemisphere) is suggested by a few studies of covert orienting (shifts in allocation of visual attention in the absence of saccadic eye movements), including one study of biological parents, suggesting the influence of genetic factors (Nigg, Swanson, Hinshaw, 1997; Pearson, Yaffee, Loveland, et al., 1995; Swanson, Posner, Potkin, 1991). However, inconsistency of findings across studies and across child and parent samples does not allow for firm conclusions.

Response inhibition deficits are demonstrated using theoretically distinct methods. One approach characterizes the impairment as delay avoidance, defined as a response style aimed at minimizing total time on task (Sonuga-Barke, Taylor, Hepenstall, 1992; Sonuga-Barke, Williams, Hall, et al., 1996). The continuity of this response style into adulthood or its variation with gender or comorbidity is unknown. Another approach demonstrates impairments in inhibiting prepotent courses of action (indexed by slow and/or variable inhibitory processes) (Oosterlaan, Logan, Sergeant, 1998; Schachar, Logan, 1990; Schachar, Tannock, Marriott, et al., 1995). The severity of impairment is attenuated in the situational and predominantly inattentive subtypes (suggesting a closer association with hyperactivity/impulsivity), as well as by comorbid anxiety (Schachar, Logan, 1990; Schachar, Tannock, Marriott, et al., 1995). These inhibition deficits are shared by other externalizing disorders (aggression, oppositional defiant disorder, conduct disorder) but are not evident in anxiety disorders or learning disabilities, suggesting some specificity with hyperactivity/impulsivity (Oosterlaan, Logan, Sergeant, 1998). Moreover, there is preliminary evidence of a link between performance decrements on response inhibition tasks and subtle anatomical anomalies in the frontal-striatal circuitry (prefrontal cortex, caudate, and globus pallidus) in children and adolescents with ADHD (Casey, Castellanos, Giedd, 1997). It is not known whether these deficits continue into adulthood, and there is little evidence that this central inhibitory control impairment relates to behavioral self-regulation (impulsivity, overactivity, inattention).

Implications for Neural Substrate and Pathophysiology of ADHD

The pattern of neuropsychological impairments associated with ADHD shows correspondence with findings of subtle anomalies in brain anatomy and neurochemistry in individuals with ADHD (Tannock, 1998). Specifically, vigilance deficits implicate neural networks in the right frontal lobe and locus ceruleus; impairments in response control and cognitively demanding information processing implicate the dopaminergically mediated “anterior” attentional system associated with anterior cingulate and frontostriatal circuitry; and the potential deficits in visuospatial orienting implicate “posterior” attentional systems comprising superior parietal cortex, pulvinar, and superior colliculus (Posner, Raichle, 1994). Moreover, the overall difficulties in dynamic, online adjustment and adaptation to changes in the immediate environment, which are evident in both clinical and cognitive studies of ADHD, implicate cerebellar networks that play a major integrative role in prediction and preparation of neural conditions needed for a particular motor or nonmotor operation (Courchesne, Allen, 1997).

Future Directions

Currently, ADHD is best characterized as reflecting a nonoptimal activation state and dysfunction in motor preparation and control (planning, execution, inhibition) not readily explainable by comorbidity, but not necessarily specific to ADHD. This research is challenged by heterogeneity of this symptom complex, measurement problems, and the study of small samples. Future studies may be more informative if ADHD is conceptualized as a composite of two quantitative, continuously distributed dimensions of inattention and impulsivity/ hyperactivity, rather than as three categorical subtypes. Also, large samples are required to afford adequate statistical power for multivariate techniques to examine the impact of gender, age, symptom dimensions, and comorbidity. Comparisons with multiple clinical/medical groups are required to examine the issue of specificity of neuropsychological impairment. Measurement approaches are required that select measures of contrasting constructs (automatic versus controlled processing, linguistic versus non-linguistic, fast versus slow pace, motoric versus nonmotoric, high versus low working memory load, etc.) and incorporate the recent advances in brain imaging and psychophysiological techniques. Delineation of the neuropsychological and neural mechanisms of ADHD must be an iterative process in which clinical subtypes are defined, tested, and redefined, using more precisely controlled and validated measures.

References

Barkley RA, Anastopoulos AD, Guevremont DC, Fletcher KE. Adolescents with ADHD: patterns of behavioral adjustment, academic functioning, and treatment utilization. J Am Acad Child Adolesc Psychiatry 1991;30:752-61.

Barkley RA, DuPaul GJ, McMurray MB. Comprehensive evaluation of attention deficit disorder with and without hyperactivity as defined by research criteria. J Consult Clin Psychol 1990;58:775-98.

Baumgaertel A, Wolraich M, Dietrich M. Comparison of diagnostic criteria for ADHD in a German elementary school sample. J Am Acad Child Adolesc Psychiatry 1995;34:629-38.

Biederman J, Faraone SV, Taylor A, Sienna M, Williamson S, Fine C. Diagnostic continuity between child and adolescent ADHD: findings from a longitudinal clinical sample. J Am Acad Child Adolesc Psychiatry 1998;37:305-13.

Casey BJ, Castellanos FX, Giedd JN, et al. Implication of right frontostriatal circuitry in response inhibition and attention-deficit/hyperactivity disorder. Am J Child Adolesc Psychiatry 1997;36:374-83.

Chee P, Logan G, Schachar R, Lindsay P, Wachsmuth R. Effects of event rate and display time on sustained attention in hyperactive, normal, and control children. J Abnorm Child Psychol 1989;17:371-91.

Cohen RA. The neuropsychology of attention. New York: Plenum Press; 1993.

Corkum PV, Seigel LS. Is the continuous performance task a valuable research tool for use with children with attention-deficit-hyperactivity disorder? J Am Acad Child Adolesc Psychiatry 1993;34:1217-39.

Courchesne E, Allen G. Prediction and preparation, fundamental functions of the cerebellum. Learning and Memory 1997;4:1-35.

Faraone SV, Biederman J, Lehman BK, Spencer T, Norman D, Seidman LJ, et al. Intellectual performance and school failure in children with attention deficit hyperactivity disorder and in their siblings. J Abnorm Psychol 1993;102:616-23.

Faraone SV, Biederman J, Weber W, Russell R. Psychiatric, neuropsychological, and psychosocial features of DSM-IV subtypes of attention-deficit/hyperactivity disorder: results from a clinically referred sample. J Am Acad Child Adolesc Psychiatry 1998;37:185-93.

Felton RH, Wood FB. Cognitive deficits in reading disability and attention deficit disorder. J Learning Disabilities 1989;22:3-13,22.

Gaub M, Carlson C. Behavioral characteristics of DSM-IV ADHD subtypes in a school-based population. J Abnorm Child Psychol 1997;25:103-11.

Gaub M, Carlson C. Gender differences in ADHD: a meta-analysis and critical review. J Am Acad Child Adolesc Psychiatry 1997;36:1036-45.

Gillberg C, Rasmussen P, Carlstrom G, Svenson B, Waldenstrom E. Perceptual, motor and attentional deficits in six-year-old children. Epidemiological aspects. J Child Psychol Psychiatry 1982;23:131-44.

Gold JM, Carpenter C, Randolph C, Goldberg TE, Weinberger DR. Auditory working memory and Wisconsin card sorting test performance in schizophrenia. Arch Gen Psychiatry 1997; 54:159-65.

Halperin JM, McKay KE. Psychological testing for child and adolescent psychiatrists: a review of the past 10 years. J Am Acad Child Adolesc Psychiatry 1998;37:575-84.

Halperin JM, Wolf LE, Greenblatt ER, Young JG. Subtype analysis of commission errors on the continuous performance test in children. Dev Neuropsychol 1991;7:207-17.

Hellgren L, Gillberg IC, Bagenholm A, Gillberg C. Children with deficits in attention, motor control, and perception (DAMP) almost grown up: psychiatric and personality disorders at age 16 years. J Child Psychol Psychiatry 1994;35:1255-71.

Hinshaw SP. Externalizing behavior problems and academic underachievement in childhood and adolescence: causal relationships and underlying mechanisms. Psychol Bull 1992;111:127-55.

Hynd GW, Lorys AR, Semrud-Clikeman M, Nieves N, Huettner MIS, Lahey BB. Attention deficit disorder without hyperactivity: a distinct behavioral and neurocognitive syndrome. J Child Neurol 1991;6(Suppl):S37-S41.

Javorsky J. An examination of youth with attention-deficit/hyperactivity disorder and language learning disabilities: a clinical study. J Learning Disabilities 1996;29:247-58.

Lahey B, Applegate B, McBurnett K, et al. DSM-IV field trials for attention deficit hyperactivity disorder in children and adolescents. Am J Psychiatry 1994;151:1673-85.

Lamminmäki T, Ahonen T, Närhi V, Lyytinen H. Attention deficit hyperactivity disorder subtypes: are there differences in academic problems? Dev Neuropsychol 1995;11:297-310.

Lezak MD. Neuropsychological Assessment. 3rd ed. New York: Oxford University Press; 1995.

Losier BJ, McGrath PJ, Klein RM. Error patterns on the continuous performance test in non-medicated and medicated samples of children with and without ADHD: a meta-analytic review. J Child Psychol Psychiatry 1996;37:971-87.

Mariani MA, Barkley RA. Neuropsychological and academic functioning in preschool boys with attention deficit hyperactivity disorder. Dev Neuropsychol 1997;13:111-29.

Marshall RM, Hynd GW, Handwerk MJ, Hal J. Academic underachievement in ADHD subtypes. J Learning Disabilities 1997;30:635-42.

Matier K, Halperin JM, Sharma V, Newcorn JH, Sathaye N. Methylphenidate response in aggressive and non-aggressive ADHD children. J Amer Acad Child and Adolesc Psychiatry 1992;31:219-25.

Matier-Sharma K, Perachio N, Newcorn N. Differential diagnosis of ADHD. Child Neuropsychiat 1995;1:118-27.

McGee R, Williams S, Moffit T, Anderson J. A comparison of 13-year-old boys with attention deficit and/or reading disorder on neuropsychological measures. J Abnorm Child Psychol 1989;17:37-53.

Newby RF, Recht DR, Caldwell J, Schaefer J. Comparison of WISC-III and WISC-R IQ changes over a 2-year time span in a sample of children with dyslexia. In: Bracken BA, McCalum RS, editors. J Psychoeducational Assessment, WISC-III Monograph; 1993. p. 87-93.

Nigg JT, Hinshaw SP, Carte ET, Treuting JJ. Neuropsychological correlates of childhood attention deficit hyperactivity disorder: explainable by comorbid disruptive behavior or reading problems? J Abnorm Psychol. In press.

Nigg JT, Swanson JM, Hinshaw SP. Covert visual spatial attention in boys with attention deficit hyperactivity disorder: lateral effects, methylphenidate response and results for parents. Neuropsychologia 1997;35:165-76.

Oosterlaan J, Logan GD, Sergeant JA. Response inhibition in AD/HD, CD, comorbid AD/HD+CD, anxious and control children: a meta-analysis of studies with the stop task. J Child Psychol Psychiatry 1998;39:411-26.

Pearson DA, Yaffee LS, Loveland KA, Norton AM. Covert visual attention in children with attention deficit hyperactivity disorder: evidence for developmental immaturity? Dev Psychopathol 1995;7:351-67.

Pennington BF. Dimensions of executive functions in normal and abnormal development. In: Krasnegor N, Lyon R, Golman-Rakic P, editors. Development of the prefrontal cortex: evolution, neurobiology, and behavior. Baltimore: Brookes; 1997. p. 265-81.

Pennington BF, Ozonoff S. Executive functions and developmental psychopathology. J Child Psychol Psychiatry 1996;37:51-87.

Posner MI, Raichle ME. Images of Mind. New York: W.H. Freeman Co; 1994. Purcell R, Maruff P, Hyrios M, Pantelis C. Neuropsychological deficits in obsessive-compulsive disorder: a comparison with unipolar depression, panic disorder, and normal controls. Arch Gen Psychiatry 1998;55:415-23.

Saklofske DH, Schwean VL, Yackalic RA, Quinn D. WISC-III and SB:FE performance of children with attention deficit disorder. Canadian J School Psychology 1994;10:167-71.

Schachar R, Logan GD. Impulsivity and inhibitory control in normal development and childhood psychopathology. Dev Psychol 1990;26:710-20.

Schachar R, Tannock R, Marriott M, Logan G. Deficient inhibitory control in attention deficit hyperactivity disorder. J Abnorm Child Psychol 1995;23:411-37.

Schwean VL, Saklofske DH. WISC-III assessment of children with attention deficit/hyperactivity disorder. In: Prifitera A, Saklofske D, editors. WISC-III Clinical Use and Interpretation. San Diego, CA: Academic Press; 1998. p. 91-118.

Seidman LJ, Biederman J, Faraone SV, Millberger S, Norman D, Sieverd K, et al. Effects of family history and comorbidity on the neuropsychological performance of children with ADHD: preliminary findings. J Am Acad Child Adolesc Psychiatry 1995;34:1015-24.

Seidman LJ, Biederman J, Faraone SV, Weber W, Mennin D, Jones J. A pilot study of neuropsychological function in girls with ADHD. J Am Acad Child Adolesc Psychiatry 1997;36:366-73.

Seidman LJ, Biederman J, Faraone SV, Weber W, Ouellette C. Toward defining a neuropsychology of attention deficit-hyperactivity disorder: performance of children and adolescents from a large clinically referred sample. J Consul and Clin Psychol 1997;65:150-60.

Semrud-Clikeman MS, Biederman J, Sprich S, Krifcher B, Norman D, Faraone SV. Comorbidity between ADHD and learning disability: a review and report in a clinically referred sample. J Am Acad Child Adolesc Psychiatry 1992;31:439-48.

Sergeant JA. Van der Meere JJ. Convergence of approaches in localizing the hyperactivity deficit. In: Lahey BB, Kazdin AE, editors. Advances in Clinical Psychology. New York: Plenum Press; 1990. p. 207-46.

Sonuga-Barke EJS, Lamparelli M, Stevenson J, Thompson M, Henry A. Behavior problems and preschool intellectual attainment: the associations of hyperactivity and conduct problems. J Child Psychiatry 1994;35:949-60.

Sonuga-Barke EJS, Taylor E, Hepenstall E. Hyperactivity and delay aversion-II: the effects of self versus externally imposed stimulus presentation periods on memory. J Child Psychol Psychiatry 1992;33:399-409.

Sonuga-Barke EJS, Williams E, Hall M, Saxton T. Hyperactivity and delay aversion III: the effects on cognitive style of imposing delay after errors. J Child Psychol Psychiatry 1996;37:189-94.

Swanson JM, Posner MI, Potkin S, Bonforte S, Youpa D, Cantwell D, Crinella F. Activating tasks for the study of visual-spatial attention in ADHD children: a cognitive anatomical approach. J Child Neurol 1991;6 (Suppl.):S119-27.

Tannock R. Attention deficit hyperactivity disorder: advances in cognitive, neurobiological, and genetic research. J Child Psychol Psychiatry 1998;39:65-99.

Tannock R, Schachar R. Executive dysfunction as an underlying mechanism of behavior and language problems in attention deficit hyperactivity disorder. In: Beitchman JH, Cohen N, Konstantareas MM, Tannock R, editors. Language, learning, and behavior disorders: developmental, biological, and clinical perspectives. New York: Cambridge University Press; 1996. p.128-55.

Tannock R, Schachar R, Logan G. Does methylphenidate induce overfocusing in hyperactive children? J Clinical Child Psychol 1993;22:28-41.

Van der Meere JJ. The role of attention. In: Sandberg ST, editor. Monographs in child and adolescent psychiatry. Hyperactivity disorders of childhood. Cambridge: Cambridge University Press; 1996. p. 109-46.

Zentall SS. Fact-retrieval automatization and math problem solving by learning disabled, attention-disordered, and normal adolescents. J Education Psychol 1990;82:856-65.

  Return to Table of Contents

Balance Check's Five Essential ADD/ADHD Books List

Balance Check's Library of ADD / ADHD Books

Balance Check's Links Pages

Balance Check's ADD Home Page