Evidence-Based Reviews

Attention-deficit/hyperactivity disorder: Tips to individualize drug therapy

Current Psychiatry. 2002 May;1(5):32-41

What help can we offer parents of children with ADHD? Can adults hope to conquer chronic attention deficits that interfere with on-the-job and social function? Here are answers, as a leading team of psychiatrists describes an up-to-date treatment approach

References

1. Goldman L, Genel M, Bezman R, Slanetz P. Diagnosis and treatment of attention-deficit/hyperactivity disorder in children and adolescents. JAMA 1998;279:1100-7.

2. Hechtman L, Weiss G. Controlled prospective fifteen-year follow-up of hyperactives as adults: mon-medical drug and alcohol use and anti-social behaviour. Can J Psychiatry 1986;31:557-67.

3. Fischer M. Persistence of ADHD into adulthood: it depends on whom you ask. The ADHD Report 1997;5:8-10.

4. Biederman J. Attention-deficit/hyperactivity disorder: a life-span perspective. J Clin Psychiatry 1998;59:4-16.

5. Barkley R. Attention-deficit/hyperactivity disorder: A handbook for diagnosis and treament (2nd ed). New York: Guilford Press, 1998.

6. Zametkin A, Liotta W. The neurobiology of attention-deficit/hyperactivity disorder. J Clin Psychiatry 1998;59:17-23.

7. Dougherty D, Bonab A, Spencer T, et al. Dopamine transporter density in patients with attention deficit hyperactivity disorder. Lancet 1999;354:2132-3.

8. Faraone SV, Biederman J, Weiffenbach B, et al. Dopamine D4 gene 7-repeat allele and attention deficit hyperactivity disorder. Am J Psychiatry 1999;156:768-70.

9. Millstein RB, Wilens TE, Biederman J, Spencer TJ. Presenting ADHD symptoms and subtypes in clincially referred adults with ADHD. J Attent Disord 1997;2:159-66.

10. Biederman J, Newcorn J, Sprich S. Comorbidity of attention deficit hyperactivity disorder with conduct, depressive, anxiety, and other disorders. Am J Psychiatry 1991;148:564-77.

11. Woznia J, Biederman J, Kiely K, et al. Mania-like symptoms suggestive of childhood-onset bipolar disorder in clinically referred children. J Am Acad Child Adolesc Psychiatry 1995;34:867-76.

12. Wilens TE, Biederman J, Mick E, Faraone SV, Spencer T. Attention deficit hyperactivity disorder (ADHD) is associated with early onset substance use disorders. J Nerv Ment Dis 1997;185:475-82.

13. Biederman J, Wilens T, Mick E, Spencer T, Faraone S. Pharmacotherapy of attention-deficit/hyperactivity disorder reduces risk for substance use disorder. Pediatrics 1999;104:e20.-

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15. Group MTS. A 14-month randomized clinical trial of treatment strategies for attention-deficit/hyperactivity disorder. The MTA Cooperative Group. Multimodal Treatment Study of Children with ADHD. Arch Gen Psychiatry 1999;56:1073-86.

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21. Spencer TJ, Biederman J, Harding M, et al. Growth deficits in ADHD children revisited: evidence for disorder-associated growth delays? J Am Acad Child Adolesc Psychiatry 1996;35:1460-9.

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Attention-deficit/hyperactivity disorder, or ADHD, affects 4% to 5% of youths worldwide and is the most common neurobehavioral disorder treated in children.¹ Recent research and clinical experience are changing our understanding of ADHD in two important ways:

First, we now recognize that ADHD is often chronic. Its symptoms and/or associated impairment persist into adolescence in approximately three-quarters of cases and into adulthood in approximately one-half of childhood cases.^2-3 Throughout the lifespan, ADHD is associated with significant psychopathology, school and occupational failure, and peer and emotional difficulties.⁴

Second, the presence of impaired cognition has largely replaced the view that ADHD was characterized primarily by overactivity and impulsivity.⁵ This insight is leading to innovations in pharmacotherapy that offer youths and adults improved control of ADHD symptoms, with less-frequent dosing and lower risk of side effects.

Neurobiology

Although the precise neurobiology of ADHD remains unknown, frontal network abnormality or frontal-striatal dysfunction appears critical.⁶ Catecholamine dysregulation affecting both the dopaminergic and noradrenergic systems appears to be important in the underlying pathophysiology.⁶ For example, a small replicated study using SPECT imaging found adults with ADHD had twice the dopamine transporter binding potential of age-matched controls.⁷ Recent data also suggest the cholinergic system is involved in mediating symptoms of ADHD, particularly attentional regulation. Data from adoption, twin, and family-genetic studies suggest a genetic contribution in ADHD, with molecular studies focusing on the dopamine D2, D4, and the dopamine transporter as candidate genes.⁸

Diagnosis

Symptoms of ADHD are related to the patient’s age at presentation. In youth, ADHD is characterized by inattention, distractibility, impulsivity, and hyperactivity excessive for the child’s developmental level.^1,5 Other symptoms include low frustration tolerance, frequent shifting of activities, difficulty organizing tasks, and daydreaming. While these symptoms are typically pervasive, they may not occur in all settings.

Older adolescents and adults tend to present with prominent attentional difficulties (distractibility, shifting activities frequently, forgetfulness, disorganization) that affect work, schooling, and relationships.⁹ These older patients frequently also manifest residual impulsivity (intrusiveness, impatience) and hyperactivity (fidgetiness, restlessness).⁶ Adults with ADHD have a history of childhood onset of the disorder, with persistence through adolescence and beyond. Diagnosis of adult ADHD requires evidence of impairment in academic, work, and interpersonal domains.

Table 1

DSM-IV CRITERIA FOR DIAGNOSING ADHD

Either (1) or (2)
Some hyperactive-impulsive or inattentive symptoms that caused impairment were present before age 7.
Some impairment from the symptoms is present in two or more settings (e.g., at school/work or at home).
There must be clear evidence of clinically significant impairment in social, academic, or occupational functioning.
The symptoms do not occur exclusively during the course of a pervasive developmental disorder, schizophrenia, or other psychiatric disorder and are not better accounted for by a mood, anxiety, dissociative, personality, or other mental disorder.

Code based on type:

314.01 ADHD, Combined Type—if both criteria A1 and A2 have been met for the past 6 months.

314.00 ADHD, Predominantly Inattentive Type—if criterion A1 has been met but criterion A2 has not been met for the past 6 months.

314.01 ADHD, Predominantly Hyperactive-Impulsive Type—if criterion A2 has been met but criterion A1 has not been met for the past 6 months.

(Specify “In partial remission” in patients whose symptoms no longer meet full criteria).

Adapted from: Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Text revision. Washington: American Psychiatric Association, 2000.

DSM-IV recognizes three subtypes of ADHD based on presenting symptoms:

predominantly inattentive (20% to 30% of cases);
predominantly hyperactive-impulsive (<15%);
combined inattentive and hyperactive-impulsive (50% to 75%).

ADHD is diagnosed by clinical history, applying DSM-IV criteria ( Table 1). Rating scales, checklists, and neuropsychological batteries—although not diagnostic—may help provide evidence for the disorder and accompanying comorbid conditions (e.g., Conners Rating Scales, Brown Rating Scales).⁵

Complicating the clinical picture of ADHD is the common co-occurrence of other psychiatric disorders. Almost three-quarters of individuals with ADHD have psychiatric comorbidity, including:

oppositional disorders (40% to 60% of ADHD cases);
conduct disorders (10% to 20%);
anxiety disorders (30% to 40%);
mood disorders (20% to 30%).¹⁰

For example, although few people with ADHD develop bipolar illness, an excess of ADHD is reported in depressed (20% to 30%) and bipolar youth (50% to 90%).¹¹ ADHD and its associated comorbid conditions also place sufferers at risk for higher rates and younger onset of cigarette smoking and substance abuse.¹² Most studies, however, indicate that pharmacotherapy reduces the risk for later drug and alcohol use disorders.¹³

Treatment

Management of ADHD includes nonpharmacologic and pharmacologic interventions.¹ Support groups (e.g., Children and Adults with Attention Deficit/Hyperactivity Disorder (CHADD), www.chadd.org) are invaluable and inexpensive sources of information about ADHD.

For children in school, a specialized educational plan with frequent re-evaluations of the child’s progress is recommended. Encourage parents to work closely with the child’s teacher, guidance counselor, or school psychologist. Children with ADHD tend to perform better in school when given structure, a predictable routine, checked homework, learning aids, and resource room time.⁵ Specific remediation plans are recommended for comorbid learning disorders, found in approximately one-third of individuals with ADHD.