Attention-Deficit Hyperactivity Disorder The 5 Minute Pediatric Consult


	Attention-Deficit Hyperactivity Disorder

Nathan J. Blum

Database
Differential Diagnosis
Data Gathering
Physical Examination
Laboratory Aids
Therapy
Follow-Up
Common Questions and Answers
Bibliography

DATABASE

DEFINITION

Attention-deficit hyperactivity disorder (ADHD) is a syndrome characterized by persistent and developmentally inappropriate levels of inattention and/or hyperactivity and impulsivity. The following disorders have been associated with an increased prevalence of ADHD:

Toxin exposures (lead toxicity, fetal alcohol syndrome)
Brain injury (traumatic, infectious)
Tourette syndrome
Genetic and metabolic disorders
Recurrent otitis media
Iron deficiency
Malnutrition

PATHOPHYSIOLOGY

Research suggests that some cases may be related to decreases in the activity of certain brain regions, particularly the frontal lobes.

The catecholamine neurotransmitters, dopamine and norepinephrine, are likely to be important, as the medications that are most effective for ADHD alter the levels of these neurotransmitters.
Family and school environments can have a major influence on ADHD symptoms

GENETICS

Risk of ADHD in first-degree relatives is approximately 25%.
Concordance in monozygotic twins: 59% to 81%; concordance in dizygotic twins: 33%

EPIDEMIOLOGY

Affects 3% to 5% of school-aged children
Male:female ratio: 4:1
Affects 1% to 2% of adults (less well studied)

COMPLICATIONS

School failure (33% kept back a grade before reaching high school)
Poor peer relationships
Sleep problems (over 50%)
Poor fine motor skills
Increased risk of accidental injury
Additional psychiatric diagnosis (over 50%)
Learning disabilities (30%)

PROGNOSIS

Many individuals with ADHD are quite successful. As a group, however, individuals with ADHD tend to complete fewer years of school and have lower occupational ranks. Children with ADHD and aggressive or antisocial behaviors are at relatively high risk for continuing to demonstrate these behaviors as adults. Thus, these children will usually need to be referred for intensive treatment, including pharmacotherapy, counseling, academic interventions, and family therapy.

DIFFERENTIAL DIAGNOSIS

Medical
- Seizures (absence)
- Hypothyroidism
- Hyperthyroidism
- Hearing impairment
- Visual impairment
- Medication side effects
- Neurodegenerative disorders (early in course)
Developmental
- Mental retardation
- Pervasive developmental disorders (autism)
Educational
- Learning disabilities
Psychiatric
- Depression
- Mania
- Anxiety disorders
- Oppositional defiant disorder
- Conduct disorder
- Obsessive-compulsive disorder
Family
- Disorganized/chaotic family environment

DATA GATHERING

HISTORY

Ask for a detailed description of behaviors (frequency, duration, intensity).

When was the onset of symptoms? Symptoms of ADHD usually present prior to age 7.
Obtain developmental, medical, family, and social history, focusing on diseases in differential diagnoses.
Does the child finish work, chores?
Does the child squirm or fidget?
Does the child lose or forget things needed for homework or other tasks?
Does the child interrupt games, questions, or conversations?
Does the child have difficulty waiting his/her turn?
How does the child attend to activities at home versus school? Discrepancy, especially if worse at home, suggests that other diagnoses should be considered.
Do problem behaviors vary across activities such as tasks versus play activities? Many children with ADHD can pay attention during play activities, but not while performing tasks.

PHYSICAL EXAMINATION

May have “soft” neurologic signs such as overflow movements, choreiform movements, finger gnosis. These are more common in children with ADHD than in controls, but are not specific.
The remainder of physical and neurological examination is usually normal.
To rule out other diagnoses: examine skin for neurocutaneous syndromes, do a thorough mental status and developmental examination, and conduct hearing and vision tests.

LABORATORY AIDS

TESTS

Rating Scales

There are many rating scales to assess ADHD (see Barkley, 1998).
Parent and teacher ratings are routine components of the assessment.
Significant discrepancy between parent and teacher ratings is a red flag.

Other Tests

Computerized continuous performance tasks are sometimes used, but scores on these tests are not sensitive in detecting ADHD.

THERAPY

Behavioral counseling and educational interventions are important components of treatment (see Mercugliano et al., 1998, for an in-depth discussion).

DRUGS

Methylphenidate (Ritalin)

Efficacy
- Eighty percent of children with ADHD improve significantly; individual response is highly variable. Teacher rating scales are helpful in documenting positive response to the medication.

Pharmacokinetics
- Onset, 20 to 30 minutes; duration, 3 to 4 hours. Slow-release form with longer duration is available.
Dose
- 0.3 to 0.6 mg/kg per dose; higher doses may be needed in some patients.
Side effects
- Common:
  - Appetite suppression
  - Insomnia
  - Stomachaches
  - Headaches
  - Note: Somatic complaints are common in children with ADHD and should be inquired about before medication is started.
- Less Common:
  - Rebound (increased activity or moodiness as medication wears off)
  - Dizziness
  - Growth suppression (at high doses)
  - Dysphoria
  - Tics (5%–10%)
  - Tourette syndrome (1%; medication may unmask underlying disorder)
  - Excessive dose may result in tired or withdrawn appearance
Interactions
- May inhibit metabolism of anticonvulsants, coumadin, tricyclic antidepressants
- Should not be used with MAO inhibitors
- Other sympathomimetic medications (e.g., ephedrine, pseudoephedrine) may increase side effects.
- Antihistamines may decrease efficacy.

Dextroamphetamine (Dexedrine, Adderall)

Effects and side effects are similar to those of methylphenidate; usual dose range, 0.15 to 3 mg/kg per dose.
Adderall and Dexedrine spansule capsules are long acting (start at 2.5–5.0 mg/d; unusual for total daily dose to exceed 30 mg).

Pemoline (Cylert)

Onset, 1 to 2 hours
Plasma half-life, 5 to 6 hours.
Usual dose, 1 to 3 mg/kg/d. Liver function tests need to be monitored. Liver failure resulting in death or liver transplantation has occurred.

OTHER MEDICATIONS

Alpha-Adrenergic Agonists

Clonidine (Catapress), Guanfacine (Tenex)
Indications
- Nonresponders to stimulants
- Hyperactivity or aggression is the major problem.
- ADHD with tics or Tourette syndrome
Side effects
- Sedation (very common)
- Rebound hypertension if medications are stopped suddenly
- Decreased blood pressure (dizziness)
- Depression

Tricyclic Antidepressants

Imipramine (Tofranil), Nortryptyline (Pamelor), Desipramine (Norpramin)
Indications
- Nonresponders to stimulants
- ADHD with tics or Tourette syndrome
- ADHD with anxiety or mood disorders
Side effects
- Anticholinergic effects
- Cardiac arrhythmias (must monitor ECGs)
- Fatigue
Warn families that overdoses can be fatal.

Atypical Antidepressants

Bupropion (Wellbutrin)
Indications
- Nonresponders to stimulants
- ADHD with anxiety or mood disorders
Side effects
- Irritability
- Insomnia
- There is limited experience in children, but in adults, drug-induced seizures can occur, especially at high doses.

FOLLOW-UP

Assess school performance.
Check for associated behavior problems.
Assess family and peer relationships.
Check for medication side effects.
Assess continuing need for medication yearly.

PITFALLS

Lack of information on symptoms from both school and home
Missing associated learning problems and/or psychiatric disorders
Individual response to stimulant medication is idiosyncratic; higher doses do not always result in improvement in symptoms.

COMMON QUESTIONS AND ANSWERS

Q: At what age can you begin to make the diagnosis of ADHD?
A: No lower limit has been identified. There is a wide range of normal activity levels and attention spans in preschool-aged children. Be cautious about making the diagnosis in children under the age of 4 years.

Q: Should stimulant medication be prescribed on weekends and over the summer?
A: Family and peer relationships of some children with ADHD benefit from use during these times; periods off medication may minimize the long-term effects on weight and growth. Children engaged in school-like or school-related tasks during the summer or on weekends may need to be on medication for these activities.

Q: Can methylphenidate be used to treat ADHD in children with tics or Tourette Syndrome?
A: Methylphenidate will cause an exacerbation of tics in some children with chronic tic disorder or Tourette syndrome. However, many children will not experience any significant change in tic frequency on methylphenidate. When methylphenidate is used for the treatment of ADHD in children with tics, the effects of the medication on the ADHD symptoms and the tics must be monitored. Tic rating scales are available to help with this monitoring.

Q: Can methylphenidate be used to treat ADHD in children with seizures?
A: Although the Physicians’ Desk Reference states that methylphenidate lowers the seizure threshold, the medication can be used in children with well-controlled seizure disorders.

ICD-9-CM 314.01

BIBLIOGRAPHY

American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 4th ed. Washington, DC: American Psychiatric Association, 1994.

Barkley RA. Attention deficit hyperactivity disorder: a handbook for diagnosis and treatment, 2nd ed. New York: Guilford, 1998.

Culbert TP, Banez GA, Reiff MI. Children who have attentional disorders: interventions. Pediatr Rev 1994:15:5–15.

Mercugliano M, Power TJ, Blum NJ. The clinician’s practical guide to attention-deficit/hyperactivity disorder. Baltimore: Brookes, 1998.

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