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- Most new cases of attention deficit– hyperactivity disorder (ADHD) are of the predominantly inattentive subtype. Research on the use of psychostimulants in these patients has shown a high rate of nonresponders.
- Although psychostimulants showed a short-term decrease in symptoms in students diagnosed with predominantly inattentive ADHD, they did not significantly improve grade-point averages.
To evaluate psychostimulants in the treatment of attention deficit–hyperactivity disorder (ADHD), predominantly inattentive subtype with coexisting academic impairment, a consecutive sample of 35 students from a private, primary care, office-based practice was followed for 1 year. All participants received psychostimulants, multimodal interventions, and treatment of comorbid disorders. Baseline mean grade-point averages (GPAs) from the preceding school year were compared with mean GPAs calculated at 1 year. Statistical analysis was by a paired samples t test.
Of 32 students who completed the study, 27 pupils’ GPAs did not improve (84.4%), while 5 pupils’ GPAs did improve (15.6%) (P=.176).
These findings call for additional research to further define predominantly inattentive ADHD in patients who present with inattention and academic concerns, and the role of stimulants in the treatment of this disorder.
Diagnostic criteria
In 1994, the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) redefined the full syndrome of attention deficit hyperactivity disorder as combined ADHD, and introduced 2 new subtypes: predominantly inattentive and predominantly hyperactive-impulsive.1 Since publication, the majority of new cases identified by DSM-IV have been predominantly inattentive ADHD.2 Primary care physicians manage 86% of patients with ADHD.3
The clinical issues
The diagnostic criteria defining predominantly inattentive ADHD and the evidence supporting its inclusion as a separate subtype mainly involve students with academic impairment.4 Measuring the effect of pharmacologic intervention on ADHD and academic functioning is important.5,6
Research on the use of psychostimulants in patients with attention deficit disorder without hyperactivity as defined by the DSM-III7 showed a high rate of nonresponders and no evidence of long-term effects on academic achievement and learning.8-10 It is not clear whether these results apply to patients with predominantly inattentive ADHD.11 A recent National Institutes of Health Consensus Statement acknowledged the need for research that specifically targets predominantly inattentive ADHD and the effects of psychotropic therapy on school performance associated with the subtype.12
The following study was therefore designed to address these issues and determine the effect of psychostimulant treatment in patients with predominantly inattentive ADHD and academic impairment.
Methods
The 35 participants from the author’s rural, office-based practice, seen because of academic concerns and inattention, were consecutively diagnosed with predominantly inattentive ADHD based on information obtained from parents and teachers and application of the DSM-IV criteria.1 Clinical examinations ruled out physical or neurologic handicaps and uncorrected visual or hearing impairments ( Table 1).
Seven participants had academic impairment as the only comorbidity with predominantly inattentive ADHD. Twenty-eight had multiple comorbidities. These included anxiety symptoms (12), dysgraphia (12), psychosomatic complaints (11), social problems (6), communication disorders (4), learning disabilities (3), enuresis (3), and dysphoria (3). Six parents of the students had a history of anxiety–depression and 2 had generalized anxiety disorder.
Anxiety symptoms, psychosomatic complaints, dysphoria, and fine-motor dyspraxia were descriptive problems and not considered disorders using DSM-IV criteria.1 Learning disabilities and communication disorders were diagnosed by school psychologists and speech language pathologists, respectively. Social impairment was diagnosed using the asocial domain on the Conner’s Teacher Rating Scale13 and noting t scores of ≥1.5 standard deviations above the mean. Enuresis was diagnosed from information obtained from the history and physical exam. None of the cohort met DSM-IV criteria for oppositional defiant disorder or conduct disorder.1
The diagnostic protocol for ADHD and coexisting disorders used in this study was consistent with the recommendations endorsed by the American Academy of Pediatrics and the American Academy of Family Physicians.14
The baseline GPA for each participant was determined by taking the GPA from each report card of the preceding school year (either four 9-week report cards or six 6-week report cards) and calculating the mean GPA. The mean GPA after the school year following psychostimulant therapy was calculated for each student in the same manner and compared with his mean baseline GPA.
Participants were assessed every 6 to 9 weeks (when they brought their report cards to the office) for compliance and possible side effects of medication. Dosage adjustments were determined by using follow-up information obtained from parents and teachers, based on DSM-IV criteria for predominantly inattentive ADHD.
All patients, families, and school personnel received educational information on predominantly inattentive ADHD throughout the study. This is consistent with the practice parameters for ADHD from the American Academy of Child and Adolescent Psychiatry and a national perspective on ADHD treatment in primary care practice settings, which states: “providing information about symptoms of ADHD, areas of impairment, etiology, and principles of behavior management to parents and teachers constitutes sound clinical practice.”15 Statistical analysis was performed by a paired samples t test.
TABLE 1
Profile of participants in study of ADHD treatment and academic performance
| Participants | Nonparticipants | GPA not improved | GPA improved | |
|---|---|---|---|---|
| Gender | ||||
| Male | 23 | 2 | 18 | 5 |
| Female | 9 | 1 | 9 | 0 |
| Mean age(mo) | 125 ± 30 | 124 ± 9.2 | 127 ± 32 | 119 ± 10 |
| Race | ||||
| White | 28 | 3 | 24 | 4 |
| African American | 4 | 0 | 3 | 1 |
| Mean GPA | 2.26 ± .62 | 2.24 ± .54 | 2.26 ± .66 | 2.24 ± .42 |
| Family structure | ||||
| Both parents | 20 | 2 | 17 | 3 |
| Blended | 8 | 1 | 6 | 2 |
| Single parent | 4 | 0 | 4 | 0 |
| Parent psychopathology | 8 | 0 | 7 | 1 |
| Mean comorbidities | 1.53 | 1.67 | 1.59 | 1.20 |
| GPA, grade-point average | ||||
Results
Thirty-two of 35 students completed the study. Using a Mann-Whitney U test, no significant differences were found between these patients and those who did not complete the study (P=.80 for baseline GPA differences and P=.80 for age.)
According to follow-up information from parents and teachers, all participants exhibited short-term improvements in DSM-IV criteria for predominantly inattentive ADHD at some point during the study. Five pupils who completed the study had improved GPAs (15.6%), while the remaining 27 participants showed no change or decreased GPAs (84.4%).
Using students t tests to compare age, baseline GPAs, and number of comorbidities and χ2 for parental psychopathology, no significant differences were found between students with improved GPAs and those without improvement in their GPAs (P=.61 for age, P=.93 for baseline GPA differences, P=.53 for differences in comorbidities, and P=.70 for differences in parental psychopathology; see Table 1). Using a paired sample t test on data from all 32 participants showed that the overall treatment effect was not significant (P=.176; see Table 2).
TABLE 2
Grade-point averages at baseline and at the study’s conclusion*
| Student # | Baseline GPAs | Treatment GPAs | Change |
|---|---|---|---|
| 1 | 2.29 | 1.59 | –.70 |
| 2 | 3.00 | 2.40 | –.60 |
| 3 | 1.80 | 1.25 | –.55 |
| 4 | 2.50 | 1.96 | –.54 |
| 5 | 2.50 | 2.00 | –.50 |
| 6 | 1.80 | 1.50 | –.30 |
| 7 | 3.50 | 3.22 | –.28 |
| 8 | 2.57 | 2.35 | –.22 |
| 9 | 2.43 | 2.29 | –.14 |
| 10 | 3.00 | 2.86 | –.14 |
| 11 | 2.25 | 2.12 | –.13 |
| 12 | 2.57 | 2.45 | –.12 |
| 13 | 2.47 | 2.37 | –.10 |
| 14 | 2.71 | 2.61 | –.10 |
| 15 | 2.20 | 2.10 | –.10 |
| 16 | 2.27 | 2.20 | –.07 |
| 17 | 1.66 | 1.59 | –.07 |
| 18 | 1.87 | 1.80 | –.07 |
| 19 | 2.43 | 2.36 | –.07 |
| 20 | .71 | .67 | –.04 |
| 21 | 2.53 | 2.50 | –.03 |
| 22 | 2.10 | 2.07 | –.03 |
| 23 | .95 | .92 | –.03 |
| 24 | 2.53 | 2.52 | –.01 |
| 25 | 3.29 | 3.29 | 0 |
| 26 | .95 | .95 | 0 |
| 27 | 2.25 | 2.25 | 0 |
| 28 | 2.17 | 2.60 | +.43 |
| 29 | 2.66 | 3.09 | +.43 |
| 30 | 2.50 | 3.00 | +.50 |
| 31 | 1.57 | 2.12 | +.55 |
| 32 | 2.29 | 2.85 | +.56 |
| Mean ± SD | 2.26 ± .62 | 2.18 ± .65 | |
| *Post-treatment GPAs declined an average of .08 ± .32, 95% confidence interval, –.19 to .04. Paired samples test=1.385 (31 degrees of freedom) (P=.176). | |||
| GPA, grade-point average; SD, standard deviation | |||
Discussion
Psychostimulant therapy did not significantly improve the outcome measures (GPAs) in the cohort diagnosed with predominantly inattentive ADHD and academic impairment. Additional comorbidities were diagnosed and treated, but differences among participants were not statistically significant. Short-term decreases in DSM-IV symptoms of predominantly inattentive ADHD did not translate into academic gains.
Limitations to the present study include the small sample size and lack of a control group. Thus, the findings should be considered preliminary. GPAs are not standardized scores and are sensitive to varying influences. However, the American Academy of Pediatrics notes that even when standardized instruments are used to assess stimulant treatment for ADHD, there is “frequently no association with improvements in academic achievement.”16 Only short-term gains in academic efficiency have been reported.17
The average doses employed (methylphenidate 16.7 mg/d, dextroamphetamine 11 mg/d) were smaller than the starting doses used successfully in the Multimodal Treatment Study of Children with ADHD (methylphenidate 30.5 mg/d, dextroamphetamine 15.25 mg/d).18 However, this study excluded patients with predominantly inattentive ADHD.19 The lower dosages used in the present study are compatible with the practice parameters of the American Academy of Child and Adolescent Psychiatry for ADHD without hyperactivity.20
All participants in the study received educational assistance. Those students not attending resource classes qualified for accommodations and modifications under Section 504 of the Rehabilitation Act of 1973 guidelines. The small sample sizes precluded an analysis of the effects of these different educational interventions on GPAs. The input from multiple teachers and classroom settings could not be delineated. However, GPAs have the advantage of being readily accessible. In addition, the findings obtained from a community-based practice with patients and families in their natural environment support the study’s results.
How do the results of the present study correlate with the literature on predominantly inattentive ADHD, and how should clinicians incorporate these data into their evaluations of students who have inattention and academic concerns? Results from the Pediatric Research in Office Settings and the Ambulatory Sentinel Practice Network21 note that there is “a lack of standardization in the primary care evaluation of attentional problems.” Inattention is not unique to predominantly inattentive ADHD. Children and adolescents with language/learning disorders,22-24 anxiety/depression,25 and family dysfunction26 are also described as inattentive.
It is difficult to define accurately what is meant by inattention in predominantly inattentive ADHD because the psychological construct of attention is not the same as that being measured behaviorally in predominantly inattentive ADHD.27 In addition, the unifying theory on ADHD, which involves deficits in behavior inhibition and executive function, does not include predominantly inattentive ADHD in the definition.28,29 The American Academy of Pediatrics concludes that with ADHD the need “to develop more valid and precise diagnostic criteria is essential.”30
The present study should be considered an introductory step in the evaluation of psychostimulant treatment in predominantly inattentive ADHD. GPAs are easily obtained by busy clinicians and are time-efficient measures of treatment outcomes. Clearly, additional research, using larger groups and controls, is needed.
ACKNOWLEDGMENTS
The author thanks Glenn N. Jones, PhD, for his assistance with the statistical analysis.
1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association; 1994.
2. Gaub M, Carlson CL. Behavioral characteristics of DSM-IV ADHD subtypes in a school-based population. J Abnorm Child Psychol 1997;25:103-111.
3. Safer DJ. Attention deficit hyperactivity disorder: pinning down the diagnosis, implementing therapy. Consultant 1996;Mar:533-545.
4. Lahey BB, Applegate B, McBurnett K, et al. DSM-IV field trials for attention deficit hyperactivity disorder in children and adolescents. Am J Psychiatry 1994;151:1673-1685.
5. Rapport MD, Denney C, DuPaul GJ, Gardner MJ. Attention deficit disorder and methylphenidate: normalization rates, clinical effectiveness, and response prediction in 76 children. J Am Acad Child Adolesc Psychiatry 1994;33:882-893.
6. Weiss M, Jain U, Garland J. Clinical suggestions for management of stimulant treatment in adolescents. Can J Psychiatry 2000;45:717-723.
7. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 3rd ed. Washington, DC: American Psychiatric Association; 1980.
8. Cantwell DP, Baker L. Attention deficit disorder with and without hyperactivity: a review and comparison of matched groups. J Am Acad Child Adolesc Psychiatry 1992;31:432-438.
9. Barkley RA, DuPaul GJ, McMurray MB. Attention deficit disorder with and without hyperactivity: clinical response to three dose levels of methylphenidate. Pediatrics 1991;87:519-531.
10. Safer DJ. Major treatment considerations for attention-deficit hyperactivity disorder. Curr Probl Pediatr 1995;25:137-143.
11. Morgan AE, Hynd GW, Riccio CA, Hall J. Validity of DSM-IV ADHD predominantly inattentive and combined types: relationship to previous DSM diagnoses/subtype differences. J Am Acad Child Adolesc Psychiatry 1996;35:325-333.
12. National Institute of Health Consensus Development Conference Statement: diagnosis and Treatment of Attention-Deficit/Hyperactivity Disorder (ADHD). J Am Acad Child Adolesc Psychiatry 2000;39:182-193.
13. Conners CK. Conner’s Rating Scales. North Tonawanda, NY: Multi-Health Systems, Inc.; 1990.
14. Herrerias CT, Perrin JM, Stein MT. The child with ADHD: using the AAP clinical practice guideline. Am Fam Physician 2001;63:1803-1810.
15. Hoagwood K, Jensen PS, Feil M, Vitiello B, Bhatara VS. Medication management of stimulants in pediatric practice settings: a national perspective. J Dev Behav Pediatr 2000;21:322-331.
16. Committee on Quality Improvement. American Academy of Pediatrics. Clinical practice guideline: treatment of the school-aged child with attention-deficit/hyperactivity disorder. Pediatrics 2001;108:1033-1044.
17. Bennett FC, Brown RT, Craver J, Anderson D. Stimulant medication for the child with attention-deficit/hyperactivity disorder. Pediatr Clin N Am 1999;46:929-944.
18. The MTA Cooperative Group. A 14-month randomized clinical trial of treatment strategies for attention-deficit/hyperactivity disorder. Arch Gen Psychiatry 1999;56:1073-1086.
19. Arnold LE, Abikoff HB, Cantwell DP, et al. National Institute of Mental Health collaborative multimodal treatment study of children with ADHD (the MTA). Arch Gen Psychiatry 1997;54:865-870.
20. Dulcan MK, Benson RS. Summary of the practice parameters for the assessment and treatment of children, adolescents, and adults with ADHD. J Am Acad Child Adolesc Psychiatry 1997;36:1311-1317.
21. Wasserman RC, Kelleher KJ, Bocian A, et al. Identification of attentional and hyperactivity problems in primary care: a report from pediatric research in office settings and the ambulatory sentinel practice network. Pediatrics 1999;103:e38.-
22. Wolraich ML, Hannah JN, Baumgaertel A, Feurer ID. Examination of DSM-IV criteria for attention deficit/hyperactivity disorder in a county-wide sample. J Devel Behav Pediatr 1998;19:162-168.
23. Rielly NE, Cunningham CE, Richards JE, Elard H, Mahoney WJ. Detecting attention deficit hyperactivity disorder in a communications clinic; diagnostic utility of the Gordon Diagnostic System. J Clin Exper Neuropsychol 1999;21:685-700.
24. Beichman JH, Cantwell DP, Forness SR, Kavale KA, Kauffman JM. Practice parameters for the assessment and treatment of children and adolescents with language and learning disorders. J Am Acad Child Adolesc Psychiatry 1998;37(suppl 10):46s-62s.
25. Zametkin AD, Ernst M. Problems in the management of attention-deficit-hyperactivity disorder. N Engl J Med 1999;340:40-46.
26. Schneider SC, Tan G. Attention-deficit hyperactivity disorder in pursuit of diagnostic accuracy. Postgrad Med 1997;101:231-240.
27. Shaywitz BA, Fletcher JM, Shaywitz SE. Attention deficit hyperactivity disorder. Adv Pediatr 1997;44:331-367.
28. Barkley RA. Behavioral inhibition, sustained attention, and executive functions: constructing a unifying theory of ADHD. Psychol Bull 1997;121:65-94.
29. Houghton S, Douglas G, West J, et al. Differential patterns of executive function in children with attention-deficit hyperactivity disorder according to gender and subtype. J Child Neurol 1999;14:801-805.
30. Committee on Quality Improvement. American Academy of Pediatrics. Clinical practice guideline: diagnosis and evaluation of the child with attention-deficit/hyperactivity disorder. Pediatrics 2000;105:1158-1170.
Correspondence: 606 Haifleigh Street, PO Box 1186, Franklin, LA 70538, E-mail: [email protected].
- Most new cases of attention deficit– hyperactivity disorder (ADHD) are of the predominantly inattentive subtype. Research on the use of psychostimulants in these patients has shown a high rate of nonresponders.
- Although psychostimulants showed a short-term decrease in symptoms in students diagnosed with predominantly inattentive ADHD, they did not significantly improve grade-point averages.
To evaluate psychostimulants in the treatment of attention deficit–hyperactivity disorder (ADHD), predominantly inattentive subtype with coexisting academic impairment, a consecutive sample of 35 students from a private, primary care, office-based practice was followed for 1 year. All participants received psychostimulants, multimodal interventions, and treatment of comorbid disorders. Baseline mean grade-point averages (GPAs) from the preceding school year were compared with mean GPAs calculated at 1 year. Statistical analysis was by a paired samples t test.
Of 32 students who completed the study, 27 pupils’ GPAs did not improve (84.4%), while 5 pupils’ GPAs did improve (15.6%) (P=.176).
These findings call for additional research to further define predominantly inattentive ADHD in patients who present with inattention and academic concerns, and the role of stimulants in the treatment of this disorder.
Diagnostic criteria
In 1994, the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) redefined the full syndrome of attention deficit hyperactivity disorder as combined ADHD, and introduced 2 new subtypes: predominantly inattentive and predominantly hyperactive-impulsive.1 Since publication, the majority of new cases identified by DSM-IV have been predominantly inattentive ADHD.2 Primary care physicians manage 86% of patients with ADHD.3
The clinical issues
The diagnostic criteria defining predominantly inattentive ADHD and the evidence supporting its inclusion as a separate subtype mainly involve students with academic impairment.4 Measuring the effect of pharmacologic intervention on ADHD and academic functioning is important.5,6
Research on the use of psychostimulants in patients with attention deficit disorder without hyperactivity as defined by the DSM-III7 showed a high rate of nonresponders and no evidence of long-term effects on academic achievement and learning.8-10 It is not clear whether these results apply to patients with predominantly inattentive ADHD.11 A recent National Institutes of Health Consensus Statement acknowledged the need for research that specifically targets predominantly inattentive ADHD and the effects of psychotropic therapy on school performance associated with the subtype.12
The following study was therefore designed to address these issues and determine the effect of psychostimulant treatment in patients with predominantly inattentive ADHD and academic impairment.
Methods
The 35 participants from the author’s rural, office-based practice, seen because of academic concerns and inattention, were consecutively diagnosed with predominantly inattentive ADHD based on information obtained from parents and teachers and application of the DSM-IV criteria.1 Clinical examinations ruled out physical or neurologic handicaps and uncorrected visual or hearing impairments ( Table 1).
Seven participants had academic impairment as the only comorbidity with predominantly inattentive ADHD. Twenty-eight had multiple comorbidities. These included anxiety symptoms (12), dysgraphia (12), psychosomatic complaints (11), social problems (6), communication disorders (4), learning disabilities (3), enuresis (3), and dysphoria (3). Six parents of the students had a history of anxiety–depression and 2 had generalized anxiety disorder.
Anxiety symptoms, psychosomatic complaints, dysphoria, and fine-motor dyspraxia were descriptive problems and not considered disorders using DSM-IV criteria.1 Learning disabilities and communication disorders were diagnosed by school psychologists and speech language pathologists, respectively. Social impairment was diagnosed using the asocial domain on the Conner’s Teacher Rating Scale13 and noting t scores of ≥1.5 standard deviations above the mean. Enuresis was diagnosed from information obtained from the history and physical exam. None of the cohort met DSM-IV criteria for oppositional defiant disorder or conduct disorder.1
The diagnostic protocol for ADHD and coexisting disorders used in this study was consistent with the recommendations endorsed by the American Academy of Pediatrics and the American Academy of Family Physicians.14
The baseline GPA for each participant was determined by taking the GPA from each report card of the preceding school year (either four 9-week report cards or six 6-week report cards) and calculating the mean GPA. The mean GPA after the school year following psychostimulant therapy was calculated for each student in the same manner and compared with his mean baseline GPA.
Participants were assessed every 6 to 9 weeks (when they brought their report cards to the office) for compliance and possible side effects of medication. Dosage adjustments were determined by using follow-up information obtained from parents and teachers, based on DSM-IV criteria for predominantly inattentive ADHD.
All patients, families, and school personnel received educational information on predominantly inattentive ADHD throughout the study. This is consistent with the practice parameters for ADHD from the American Academy of Child and Adolescent Psychiatry and a national perspective on ADHD treatment in primary care practice settings, which states: “providing information about symptoms of ADHD, areas of impairment, etiology, and principles of behavior management to parents and teachers constitutes sound clinical practice.”15 Statistical analysis was performed by a paired samples t test.
TABLE 1
Profile of participants in study of ADHD treatment and academic performance
| Participants | Nonparticipants | GPA not improved | GPA improved | |
|---|---|---|---|---|
| Gender | ||||
| Male | 23 | 2 | 18 | 5 |
| Female | 9 | 1 | 9 | 0 |
| Mean age(mo) | 125 ± 30 | 124 ± 9.2 | 127 ± 32 | 119 ± 10 |
| Race | ||||
| White | 28 | 3 | 24 | 4 |
| African American | 4 | 0 | 3 | 1 |
| Mean GPA | 2.26 ± .62 | 2.24 ± .54 | 2.26 ± .66 | 2.24 ± .42 |
| Family structure | ||||
| Both parents | 20 | 2 | 17 | 3 |
| Blended | 8 | 1 | 6 | 2 |
| Single parent | 4 | 0 | 4 | 0 |
| Parent psychopathology | 8 | 0 | 7 | 1 |
| Mean comorbidities | 1.53 | 1.67 | 1.59 | 1.20 |
| GPA, grade-point average | ||||
Results
Thirty-two of 35 students completed the study. Using a Mann-Whitney U test, no significant differences were found between these patients and those who did not complete the study (P=.80 for baseline GPA differences and P=.80 for age.)
According to follow-up information from parents and teachers, all participants exhibited short-term improvements in DSM-IV criteria for predominantly inattentive ADHD at some point during the study. Five pupils who completed the study had improved GPAs (15.6%), while the remaining 27 participants showed no change or decreased GPAs (84.4%).
Using students t tests to compare age, baseline GPAs, and number of comorbidities and χ2 for parental psychopathology, no significant differences were found between students with improved GPAs and those without improvement in their GPAs (P=.61 for age, P=.93 for baseline GPA differences, P=.53 for differences in comorbidities, and P=.70 for differences in parental psychopathology; see Table 1). Using a paired sample t test on data from all 32 participants showed that the overall treatment effect was not significant (P=.176; see Table 2).
TABLE 2
Grade-point averages at baseline and at the study’s conclusion*
| Student # | Baseline GPAs | Treatment GPAs | Change |
|---|---|---|---|
| 1 | 2.29 | 1.59 | –.70 |
| 2 | 3.00 | 2.40 | –.60 |
| 3 | 1.80 | 1.25 | –.55 |
| 4 | 2.50 | 1.96 | –.54 |
| 5 | 2.50 | 2.00 | –.50 |
| 6 | 1.80 | 1.50 | –.30 |
| 7 | 3.50 | 3.22 | –.28 |
| 8 | 2.57 | 2.35 | –.22 |
| 9 | 2.43 | 2.29 | –.14 |
| 10 | 3.00 | 2.86 | –.14 |
| 11 | 2.25 | 2.12 | –.13 |
| 12 | 2.57 | 2.45 | –.12 |
| 13 | 2.47 | 2.37 | –.10 |
| 14 | 2.71 | 2.61 | –.10 |
| 15 | 2.20 | 2.10 | –.10 |
| 16 | 2.27 | 2.20 | –.07 |
| 17 | 1.66 | 1.59 | –.07 |
| 18 | 1.87 | 1.80 | –.07 |
| 19 | 2.43 | 2.36 | –.07 |
| 20 | .71 | .67 | –.04 |
| 21 | 2.53 | 2.50 | –.03 |
| 22 | 2.10 | 2.07 | –.03 |
| 23 | .95 | .92 | –.03 |
| 24 | 2.53 | 2.52 | –.01 |
| 25 | 3.29 | 3.29 | 0 |
| 26 | .95 | .95 | 0 |
| 27 | 2.25 | 2.25 | 0 |
| 28 | 2.17 | 2.60 | +.43 |
| 29 | 2.66 | 3.09 | +.43 |
| 30 | 2.50 | 3.00 | +.50 |
| 31 | 1.57 | 2.12 | +.55 |
| 32 | 2.29 | 2.85 | +.56 |
| Mean ± SD | 2.26 ± .62 | 2.18 ± .65 | |
| *Post-treatment GPAs declined an average of .08 ± .32, 95% confidence interval, –.19 to .04. Paired samples test=1.385 (31 degrees of freedom) (P=.176). | |||
| GPA, grade-point average; SD, standard deviation | |||
Discussion
Psychostimulant therapy did not significantly improve the outcome measures (GPAs) in the cohort diagnosed with predominantly inattentive ADHD and academic impairment. Additional comorbidities were diagnosed and treated, but differences among participants were not statistically significant. Short-term decreases in DSM-IV symptoms of predominantly inattentive ADHD did not translate into academic gains.
Limitations to the present study include the small sample size and lack of a control group. Thus, the findings should be considered preliminary. GPAs are not standardized scores and are sensitive to varying influences. However, the American Academy of Pediatrics notes that even when standardized instruments are used to assess stimulant treatment for ADHD, there is “frequently no association with improvements in academic achievement.”16 Only short-term gains in academic efficiency have been reported.17
The average doses employed (methylphenidate 16.7 mg/d, dextroamphetamine 11 mg/d) were smaller than the starting doses used successfully in the Multimodal Treatment Study of Children with ADHD (methylphenidate 30.5 mg/d, dextroamphetamine 15.25 mg/d).18 However, this study excluded patients with predominantly inattentive ADHD.19 The lower dosages used in the present study are compatible with the practice parameters of the American Academy of Child and Adolescent Psychiatry for ADHD without hyperactivity.20
All participants in the study received educational assistance. Those students not attending resource classes qualified for accommodations and modifications under Section 504 of the Rehabilitation Act of 1973 guidelines. The small sample sizes precluded an analysis of the effects of these different educational interventions on GPAs. The input from multiple teachers and classroom settings could not be delineated. However, GPAs have the advantage of being readily accessible. In addition, the findings obtained from a community-based practice with patients and families in their natural environment support the study’s results.
How do the results of the present study correlate with the literature on predominantly inattentive ADHD, and how should clinicians incorporate these data into their evaluations of students who have inattention and academic concerns? Results from the Pediatric Research in Office Settings and the Ambulatory Sentinel Practice Network21 note that there is “a lack of standardization in the primary care evaluation of attentional problems.” Inattention is not unique to predominantly inattentive ADHD. Children and adolescents with language/learning disorders,22-24 anxiety/depression,25 and family dysfunction26 are also described as inattentive.
It is difficult to define accurately what is meant by inattention in predominantly inattentive ADHD because the psychological construct of attention is not the same as that being measured behaviorally in predominantly inattentive ADHD.27 In addition, the unifying theory on ADHD, which involves deficits in behavior inhibition and executive function, does not include predominantly inattentive ADHD in the definition.28,29 The American Academy of Pediatrics concludes that with ADHD the need “to develop more valid and precise diagnostic criteria is essential.”30
The present study should be considered an introductory step in the evaluation of psychostimulant treatment in predominantly inattentive ADHD. GPAs are easily obtained by busy clinicians and are time-efficient measures of treatment outcomes. Clearly, additional research, using larger groups and controls, is needed.
ACKNOWLEDGMENTS
The author thanks Glenn N. Jones, PhD, for his assistance with the statistical analysis.
- Most new cases of attention deficit– hyperactivity disorder (ADHD) are of the predominantly inattentive subtype. Research on the use of psychostimulants in these patients has shown a high rate of nonresponders.
- Although psychostimulants showed a short-term decrease in symptoms in students diagnosed with predominantly inattentive ADHD, they did not significantly improve grade-point averages.
To evaluate psychostimulants in the treatment of attention deficit–hyperactivity disorder (ADHD), predominantly inattentive subtype with coexisting academic impairment, a consecutive sample of 35 students from a private, primary care, office-based practice was followed for 1 year. All participants received psychostimulants, multimodal interventions, and treatment of comorbid disorders. Baseline mean grade-point averages (GPAs) from the preceding school year were compared with mean GPAs calculated at 1 year. Statistical analysis was by a paired samples t test.
Of 32 students who completed the study, 27 pupils’ GPAs did not improve (84.4%), while 5 pupils’ GPAs did improve (15.6%) (P=.176).
These findings call for additional research to further define predominantly inattentive ADHD in patients who present with inattention and academic concerns, and the role of stimulants in the treatment of this disorder.
Diagnostic criteria
In 1994, the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) redefined the full syndrome of attention deficit hyperactivity disorder as combined ADHD, and introduced 2 new subtypes: predominantly inattentive and predominantly hyperactive-impulsive.1 Since publication, the majority of new cases identified by DSM-IV have been predominantly inattentive ADHD.2 Primary care physicians manage 86% of patients with ADHD.3
The clinical issues
The diagnostic criteria defining predominantly inattentive ADHD and the evidence supporting its inclusion as a separate subtype mainly involve students with academic impairment.4 Measuring the effect of pharmacologic intervention on ADHD and academic functioning is important.5,6
Research on the use of psychostimulants in patients with attention deficit disorder without hyperactivity as defined by the DSM-III7 showed a high rate of nonresponders and no evidence of long-term effects on academic achievement and learning.8-10 It is not clear whether these results apply to patients with predominantly inattentive ADHD.11 A recent National Institutes of Health Consensus Statement acknowledged the need for research that specifically targets predominantly inattentive ADHD and the effects of psychotropic therapy on school performance associated with the subtype.12
The following study was therefore designed to address these issues and determine the effect of psychostimulant treatment in patients with predominantly inattentive ADHD and academic impairment.
Methods
The 35 participants from the author’s rural, office-based practice, seen because of academic concerns and inattention, were consecutively diagnosed with predominantly inattentive ADHD based on information obtained from parents and teachers and application of the DSM-IV criteria.1 Clinical examinations ruled out physical or neurologic handicaps and uncorrected visual or hearing impairments ( Table 1).
Seven participants had academic impairment as the only comorbidity with predominantly inattentive ADHD. Twenty-eight had multiple comorbidities. These included anxiety symptoms (12), dysgraphia (12), psychosomatic complaints (11), social problems (6), communication disorders (4), learning disabilities (3), enuresis (3), and dysphoria (3). Six parents of the students had a history of anxiety–depression and 2 had generalized anxiety disorder.
Anxiety symptoms, psychosomatic complaints, dysphoria, and fine-motor dyspraxia were descriptive problems and not considered disorders using DSM-IV criteria.1 Learning disabilities and communication disorders were diagnosed by school psychologists and speech language pathologists, respectively. Social impairment was diagnosed using the asocial domain on the Conner’s Teacher Rating Scale13 and noting t scores of ≥1.5 standard deviations above the mean. Enuresis was diagnosed from information obtained from the history and physical exam. None of the cohort met DSM-IV criteria for oppositional defiant disorder or conduct disorder.1
The diagnostic protocol for ADHD and coexisting disorders used in this study was consistent with the recommendations endorsed by the American Academy of Pediatrics and the American Academy of Family Physicians.14
The baseline GPA for each participant was determined by taking the GPA from each report card of the preceding school year (either four 9-week report cards or six 6-week report cards) and calculating the mean GPA. The mean GPA after the school year following psychostimulant therapy was calculated for each student in the same manner and compared with his mean baseline GPA.
Participants were assessed every 6 to 9 weeks (when they brought their report cards to the office) for compliance and possible side effects of medication. Dosage adjustments were determined by using follow-up information obtained from parents and teachers, based on DSM-IV criteria for predominantly inattentive ADHD.
All patients, families, and school personnel received educational information on predominantly inattentive ADHD throughout the study. This is consistent with the practice parameters for ADHD from the American Academy of Child and Adolescent Psychiatry and a national perspective on ADHD treatment in primary care practice settings, which states: “providing information about symptoms of ADHD, areas of impairment, etiology, and principles of behavior management to parents and teachers constitutes sound clinical practice.”15 Statistical analysis was performed by a paired samples t test.
TABLE 1
Profile of participants in study of ADHD treatment and academic performance
| Participants | Nonparticipants | GPA not improved | GPA improved | |
|---|---|---|---|---|
| Gender | ||||
| Male | 23 | 2 | 18 | 5 |
| Female | 9 | 1 | 9 | 0 |
| Mean age(mo) | 125 ± 30 | 124 ± 9.2 | 127 ± 32 | 119 ± 10 |
| Race | ||||
| White | 28 | 3 | 24 | 4 |
| African American | 4 | 0 | 3 | 1 |
| Mean GPA | 2.26 ± .62 | 2.24 ± .54 | 2.26 ± .66 | 2.24 ± .42 |
| Family structure | ||||
| Both parents | 20 | 2 | 17 | 3 |
| Blended | 8 | 1 | 6 | 2 |
| Single parent | 4 | 0 | 4 | 0 |
| Parent psychopathology | 8 | 0 | 7 | 1 |
| Mean comorbidities | 1.53 | 1.67 | 1.59 | 1.20 |
| GPA, grade-point average | ||||
Results
Thirty-two of 35 students completed the study. Using a Mann-Whitney U test, no significant differences were found between these patients and those who did not complete the study (P=.80 for baseline GPA differences and P=.80 for age.)
According to follow-up information from parents and teachers, all participants exhibited short-term improvements in DSM-IV criteria for predominantly inattentive ADHD at some point during the study. Five pupils who completed the study had improved GPAs (15.6%), while the remaining 27 participants showed no change or decreased GPAs (84.4%).
Using students t tests to compare age, baseline GPAs, and number of comorbidities and χ2 for parental psychopathology, no significant differences were found between students with improved GPAs and those without improvement in their GPAs (P=.61 for age, P=.93 for baseline GPA differences, P=.53 for differences in comorbidities, and P=.70 for differences in parental psychopathology; see Table 1). Using a paired sample t test on data from all 32 participants showed that the overall treatment effect was not significant (P=.176; see Table 2).
TABLE 2
Grade-point averages at baseline and at the study’s conclusion*
| Student # | Baseline GPAs | Treatment GPAs | Change |
|---|---|---|---|
| 1 | 2.29 | 1.59 | –.70 |
| 2 | 3.00 | 2.40 | –.60 |
| 3 | 1.80 | 1.25 | –.55 |
| 4 | 2.50 | 1.96 | –.54 |
| 5 | 2.50 | 2.00 | –.50 |
| 6 | 1.80 | 1.50 | –.30 |
| 7 | 3.50 | 3.22 | –.28 |
| 8 | 2.57 | 2.35 | –.22 |
| 9 | 2.43 | 2.29 | –.14 |
| 10 | 3.00 | 2.86 | –.14 |
| 11 | 2.25 | 2.12 | –.13 |
| 12 | 2.57 | 2.45 | –.12 |
| 13 | 2.47 | 2.37 | –.10 |
| 14 | 2.71 | 2.61 | –.10 |
| 15 | 2.20 | 2.10 | –.10 |
| 16 | 2.27 | 2.20 | –.07 |
| 17 | 1.66 | 1.59 | –.07 |
| 18 | 1.87 | 1.80 | –.07 |
| 19 | 2.43 | 2.36 | –.07 |
| 20 | .71 | .67 | –.04 |
| 21 | 2.53 | 2.50 | –.03 |
| 22 | 2.10 | 2.07 | –.03 |
| 23 | .95 | .92 | –.03 |
| 24 | 2.53 | 2.52 | –.01 |
| 25 | 3.29 | 3.29 | 0 |
| 26 | .95 | .95 | 0 |
| 27 | 2.25 | 2.25 | 0 |
| 28 | 2.17 | 2.60 | +.43 |
| 29 | 2.66 | 3.09 | +.43 |
| 30 | 2.50 | 3.00 | +.50 |
| 31 | 1.57 | 2.12 | +.55 |
| 32 | 2.29 | 2.85 | +.56 |
| Mean ± SD | 2.26 ± .62 | 2.18 ± .65 | |
| *Post-treatment GPAs declined an average of .08 ± .32, 95% confidence interval, –.19 to .04. Paired samples test=1.385 (31 degrees of freedom) (P=.176). | |||
| GPA, grade-point average; SD, standard deviation | |||
Discussion
Psychostimulant therapy did not significantly improve the outcome measures (GPAs) in the cohort diagnosed with predominantly inattentive ADHD and academic impairment. Additional comorbidities were diagnosed and treated, but differences among participants were not statistically significant. Short-term decreases in DSM-IV symptoms of predominantly inattentive ADHD did not translate into academic gains.
Limitations to the present study include the small sample size and lack of a control group. Thus, the findings should be considered preliminary. GPAs are not standardized scores and are sensitive to varying influences. However, the American Academy of Pediatrics notes that even when standardized instruments are used to assess stimulant treatment for ADHD, there is “frequently no association with improvements in academic achievement.”16 Only short-term gains in academic efficiency have been reported.17
The average doses employed (methylphenidate 16.7 mg/d, dextroamphetamine 11 mg/d) were smaller than the starting doses used successfully in the Multimodal Treatment Study of Children with ADHD (methylphenidate 30.5 mg/d, dextroamphetamine 15.25 mg/d).18 However, this study excluded patients with predominantly inattentive ADHD.19 The lower dosages used in the present study are compatible with the practice parameters of the American Academy of Child and Adolescent Psychiatry for ADHD without hyperactivity.20
All participants in the study received educational assistance. Those students not attending resource classes qualified for accommodations and modifications under Section 504 of the Rehabilitation Act of 1973 guidelines. The small sample sizes precluded an analysis of the effects of these different educational interventions on GPAs. The input from multiple teachers and classroom settings could not be delineated. However, GPAs have the advantage of being readily accessible. In addition, the findings obtained from a community-based practice with patients and families in their natural environment support the study’s results.
How do the results of the present study correlate with the literature on predominantly inattentive ADHD, and how should clinicians incorporate these data into their evaluations of students who have inattention and academic concerns? Results from the Pediatric Research in Office Settings and the Ambulatory Sentinel Practice Network21 note that there is “a lack of standardization in the primary care evaluation of attentional problems.” Inattention is not unique to predominantly inattentive ADHD. Children and adolescents with language/learning disorders,22-24 anxiety/depression,25 and family dysfunction26 are also described as inattentive.
It is difficult to define accurately what is meant by inattention in predominantly inattentive ADHD because the psychological construct of attention is not the same as that being measured behaviorally in predominantly inattentive ADHD.27 In addition, the unifying theory on ADHD, which involves deficits in behavior inhibition and executive function, does not include predominantly inattentive ADHD in the definition.28,29 The American Academy of Pediatrics concludes that with ADHD the need “to develop more valid and precise diagnostic criteria is essential.”30
The present study should be considered an introductory step in the evaluation of psychostimulant treatment in predominantly inattentive ADHD. GPAs are easily obtained by busy clinicians and are time-efficient measures of treatment outcomes. Clearly, additional research, using larger groups and controls, is needed.
ACKNOWLEDGMENTS
The author thanks Glenn N. Jones, PhD, for his assistance with the statistical analysis.
1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association; 1994.
2. Gaub M, Carlson CL. Behavioral characteristics of DSM-IV ADHD subtypes in a school-based population. J Abnorm Child Psychol 1997;25:103-111.
3. Safer DJ. Attention deficit hyperactivity disorder: pinning down the diagnosis, implementing therapy. Consultant 1996;Mar:533-545.
4. Lahey BB, Applegate B, McBurnett K, et al. DSM-IV field trials for attention deficit hyperactivity disorder in children and adolescents. Am J Psychiatry 1994;151:1673-1685.
5. Rapport MD, Denney C, DuPaul GJ, Gardner MJ. Attention deficit disorder and methylphenidate: normalization rates, clinical effectiveness, and response prediction in 76 children. J Am Acad Child Adolesc Psychiatry 1994;33:882-893.
6. Weiss M, Jain U, Garland J. Clinical suggestions for management of stimulant treatment in adolescents. Can J Psychiatry 2000;45:717-723.
7. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 3rd ed. Washington, DC: American Psychiatric Association; 1980.
8. Cantwell DP, Baker L. Attention deficit disorder with and without hyperactivity: a review and comparison of matched groups. J Am Acad Child Adolesc Psychiatry 1992;31:432-438.
9. Barkley RA, DuPaul GJ, McMurray MB. Attention deficit disorder with and without hyperactivity: clinical response to three dose levels of methylphenidate. Pediatrics 1991;87:519-531.
10. Safer DJ. Major treatment considerations for attention-deficit hyperactivity disorder. Curr Probl Pediatr 1995;25:137-143.
11. Morgan AE, Hynd GW, Riccio CA, Hall J. Validity of DSM-IV ADHD predominantly inattentive and combined types: relationship to previous DSM diagnoses/subtype differences. J Am Acad Child Adolesc Psychiatry 1996;35:325-333.
12. National Institute of Health Consensus Development Conference Statement: diagnosis and Treatment of Attention-Deficit/Hyperactivity Disorder (ADHD). J Am Acad Child Adolesc Psychiatry 2000;39:182-193.
13. Conners CK. Conner’s Rating Scales. North Tonawanda, NY: Multi-Health Systems, Inc.; 1990.
14. Herrerias CT, Perrin JM, Stein MT. The child with ADHD: using the AAP clinical practice guideline. Am Fam Physician 2001;63:1803-1810.
15. Hoagwood K, Jensen PS, Feil M, Vitiello B, Bhatara VS. Medication management of stimulants in pediatric practice settings: a national perspective. J Dev Behav Pediatr 2000;21:322-331.
16. Committee on Quality Improvement. American Academy of Pediatrics. Clinical practice guideline: treatment of the school-aged child with attention-deficit/hyperactivity disorder. Pediatrics 2001;108:1033-1044.
17. Bennett FC, Brown RT, Craver J, Anderson D. Stimulant medication for the child with attention-deficit/hyperactivity disorder. Pediatr Clin N Am 1999;46:929-944.
18. The MTA Cooperative Group. A 14-month randomized clinical trial of treatment strategies for attention-deficit/hyperactivity disorder. Arch Gen Psychiatry 1999;56:1073-1086.
19. Arnold LE, Abikoff HB, Cantwell DP, et al. National Institute of Mental Health collaborative multimodal treatment study of children with ADHD (the MTA). Arch Gen Psychiatry 1997;54:865-870.
20. Dulcan MK, Benson RS. Summary of the practice parameters for the assessment and treatment of children, adolescents, and adults with ADHD. J Am Acad Child Adolesc Psychiatry 1997;36:1311-1317.
21. Wasserman RC, Kelleher KJ, Bocian A, et al. Identification of attentional and hyperactivity problems in primary care: a report from pediatric research in office settings and the ambulatory sentinel practice network. Pediatrics 1999;103:e38.-
22. Wolraich ML, Hannah JN, Baumgaertel A, Feurer ID. Examination of DSM-IV criteria for attention deficit/hyperactivity disorder in a county-wide sample. J Devel Behav Pediatr 1998;19:162-168.
23. Rielly NE, Cunningham CE, Richards JE, Elard H, Mahoney WJ. Detecting attention deficit hyperactivity disorder in a communications clinic; diagnostic utility of the Gordon Diagnostic System. J Clin Exper Neuropsychol 1999;21:685-700.
24. Beichman JH, Cantwell DP, Forness SR, Kavale KA, Kauffman JM. Practice parameters for the assessment and treatment of children and adolescents with language and learning disorders. J Am Acad Child Adolesc Psychiatry 1998;37(suppl 10):46s-62s.
25. Zametkin AD, Ernst M. Problems in the management of attention-deficit-hyperactivity disorder. N Engl J Med 1999;340:40-46.
26. Schneider SC, Tan G. Attention-deficit hyperactivity disorder in pursuit of diagnostic accuracy. Postgrad Med 1997;101:231-240.
27. Shaywitz BA, Fletcher JM, Shaywitz SE. Attention deficit hyperactivity disorder. Adv Pediatr 1997;44:331-367.
28. Barkley RA. Behavioral inhibition, sustained attention, and executive functions: constructing a unifying theory of ADHD. Psychol Bull 1997;121:65-94.
29. Houghton S, Douglas G, West J, et al. Differential patterns of executive function in children with attention-deficit hyperactivity disorder according to gender and subtype. J Child Neurol 1999;14:801-805.
30. Committee on Quality Improvement. American Academy of Pediatrics. Clinical practice guideline: diagnosis and evaluation of the child with attention-deficit/hyperactivity disorder. Pediatrics 2000;105:1158-1170.
Correspondence: 606 Haifleigh Street, PO Box 1186, Franklin, LA 70538, E-mail: [email protected].
1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association; 1994.
2. Gaub M, Carlson CL. Behavioral characteristics of DSM-IV ADHD subtypes in a school-based population. J Abnorm Child Psychol 1997;25:103-111.
3. Safer DJ. Attention deficit hyperactivity disorder: pinning down the diagnosis, implementing therapy. Consultant 1996;Mar:533-545.
4. Lahey BB, Applegate B, McBurnett K, et al. DSM-IV field trials for attention deficit hyperactivity disorder in children and adolescents. Am J Psychiatry 1994;151:1673-1685.
5. Rapport MD, Denney C, DuPaul GJ, Gardner MJ. Attention deficit disorder and methylphenidate: normalization rates, clinical effectiveness, and response prediction in 76 children. J Am Acad Child Adolesc Psychiatry 1994;33:882-893.
6. Weiss M, Jain U, Garland J. Clinical suggestions for management of stimulant treatment in adolescents. Can J Psychiatry 2000;45:717-723.
7. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 3rd ed. Washington, DC: American Psychiatric Association; 1980.
8. Cantwell DP, Baker L. Attention deficit disorder with and without hyperactivity: a review and comparison of matched groups. J Am Acad Child Adolesc Psychiatry 1992;31:432-438.
9. Barkley RA, DuPaul GJ, McMurray MB. Attention deficit disorder with and without hyperactivity: clinical response to three dose levels of methylphenidate. Pediatrics 1991;87:519-531.
10. Safer DJ. Major treatment considerations for attention-deficit hyperactivity disorder. Curr Probl Pediatr 1995;25:137-143.
11. Morgan AE, Hynd GW, Riccio CA, Hall J. Validity of DSM-IV ADHD predominantly inattentive and combined types: relationship to previous DSM diagnoses/subtype differences. J Am Acad Child Adolesc Psychiatry 1996;35:325-333.
12. National Institute of Health Consensus Development Conference Statement: diagnosis and Treatment of Attention-Deficit/Hyperactivity Disorder (ADHD). J Am Acad Child Adolesc Psychiatry 2000;39:182-193.
13. Conners CK. Conner’s Rating Scales. North Tonawanda, NY: Multi-Health Systems, Inc.; 1990.
14. Herrerias CT, Perrin JM, Stein MT. The child with ADHD: using the AAP clinical practice guideline. Am Fam Physician 2001;63:1803-1810.
15. Hoagwood K, Jensen PS, Feil M, Vitiello B, Bhatara VS. Medication management of stimulants in pediatric practice settings: a national perspective. J Dev Behav Pediatr 2000;21:322-331.
16. Committee on Quality Improvement. American Academy of Pediatrics. Clinical practice guideline: treatment of the school-aged child with attention-deficit/hyperactivity disorder. Pediatrics 2001;108:1033-1044.
17. Bennett FC, Brown RT, Craver J, Anderson D. Stimulant medication for the child with attention-deficit/hyperactivity disorder. Pediatr Clin N Am 1999;46:929-944.
18. The MTA Cooperative Group. A 14-month randomized clinical trial of treatment strategies for attention-deficit/hyperactivity disorder. Arch Gen Psychiatry 1999;56:1073-1086.
19. Arnold LE, Abikoff HB, Cantwell DP, et al. National Institute of Mental Health collaborative multimodal treatment study of children with ADHD (the MTA). Arch Gen Psychiatry 1997;54:865-870.
20. Dulcan MK, Benson RS. Summary of the practice parameters for the assessment and treatment of children, adolescents, and adults with ADHD. J Am Acad Child Adolesc Psychiatry 1997;36:1311-1317.
21. Wasserman RC, Kelleher KJ, Bocian A, et al. Identification of attentional and hyperactivity problems in primary care: a report from pediatric research in office settings and the ambulatory sentinel practice network. Pediatrics 1999;103:e38.-
22. Wolraich ML, Hannah JN, Baumgaertel A, Feurer ID. Examination of DSM-IV criteria for attention deficit/hyperactivity disorder in a county-wide sample. J Devel Behav Pediatr 1998;19:162-168.
23. Rielly NE, Cunningham CE, Richards JE, Elard H, Mahoney WJ. Detecting attention deficit hyperactivity disorder in a communications clinic; diagnostic utility of the Gordon Diagnostic System. J Clin Exper Neuropsychol 1999;21:685-700.
24. Beichman JH, Cantwell DP, Forness SR, Kavale KA, Kauffman JM. Practice parameters for the assessment and treatment of children and adolescents with language and learning disorders. J Am Acad Child Adolesc Psychiatry 1998;37(suppl 10):46s-62s.
25. Zametkin AD, Ernst M. Problems in the management of attention-deficit-hyperactivity disorder. N Engl J Med 1999;340:40-46.
26. Schneider SC, Tan G. Attention-deficit hyperactivity disorder in pursuit of diagnostic accuracy. Postgrad Med 1997;101:231-240.
27. Shaywitz BA, Fletcher JM, Shaywitz SE. Attention deficit hyperactivity disorder. Adv Pediatr 1997;44:331-367.
28. Barkley RA. Behavioral inhibition, sustained attention, and executive functions: constructing a unifying theory of ADHD. Psychol Bull 1997;121:65-94.
29. Houghton S, Douglas G, West J, et al. Differential patterns of executive function in children with attention-deficit hyperactivity disorder according to gender and subtype. J Child Neurol 1999;14:801-805.
30. Committee on Quality Improvement. American Academy of Pediatrics. Clinical practice guideline: diagnosis and evaluation of the child with attention-deficit/hyperactivity disorder. Pediatrics 2000;105:1158-1170.
Correspondence: 606 Haifleigh Street, PO Box 1186, Franklin, LA 70538, E-mail: [email protected].