- 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.