ATTENTION DEFICIT-HYPERACTIVITY DISORDER
I. Epidemiology
- Various studies have found prevalence of 5-10% in school-aged children but
used self-reporting rather than direct testing to confirm the diagnosis.
- Some studies suggest frequent comorbidities including oppositional defiant
disorder and conduct disorder
- Risk factors include possibly some genetic factors, perinatal stres, low
birth weight, traumatic brain injury, and maternal smoking during pregnancy.
II. DSM-IV-TR diagnostic criteria (2000):
- EITHER (1) or (2) below
- Six or more of the following symptoms of inattention for > 6mos to a degree that is maladaptive and inconsistent with developmental level:
- Often fails to give close attention to details or makes careless mistakes in schoolwork, work, or other activities
- Often has difficulty sustaining attention in tasks or play activities
- Often does not seem to listen when spoken to directly
- Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (not due to
oppositional behavior or failure to understand instructions)
- Often has difficulty organizing tasks and activities
- Often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort (such as schoolwork or homework)
- Often loses things necessary for tasks or activities (e.g., toys, school assignments, pencils, books, or tools)
- Is often easily distracted by extraneous stimuli
- Is often forgetful in daily activities
- Six (or more) of the following symptoms of hyperactivity-impulsivity have persisted for at least 6 months to a degree that is maladaptive and inconsistent with developmental level:
- Often fidgets with hands or feet or squirms in seat
- Often leaves seat in classroom or in other situations in which remaining seated is expected
- Often runs about or climbs excessively in situations in which it is inappropriate (in adolescents or adults, may be limited to
subjective feelings of restlessness)
- Often has difficulty playing or engaging in leisure activities quietly
- Often "on the go" or often acts as if "driven by a motor"
- Often talks excessively
- Often blurts out answers before questions have been completed
- Often has difficulty awaiting turn
- Often interrupts or intrudes on others (e.g., butts into conversations or games)
- Some hyperactive-impulsive or inattentive symptoms that caused impairment were present before age 7 years.
- Some impairment from the symptoms is present in two or more settings (e.g., at school [or work] and 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 Psychotic Disorder and are not better accounted for by another mental disorder (e.g., Mood Disorder, Anxiety Disorder, Dissociative Disorder, or a Personality Disorder).
III. Helpful rating scales in assessing children with suspected ADHD (per
AACAP guidelines 2008):

IV. Pharmacologic treatment:
Stimulants (e.g. methylphenidate and amphetamine)
- Primarily alter dopaminergic transmission
- In a case-control study of 564 children 7-19yo
with no h/o cardiac or other chronic illness who sustained sudden death,
with 564 children who died as passengers in MVAs, , sudden-death group had
sig. higher likelihood (OR 7.4) of being on stimulant medication. (Am.
J. Psychiat. 6/15/09; ePublication ahead of print-JW) JW editor
advises precautions for children on stimulants of "a cardiac history
and physical examination for previously undetected cardiac abnormalities,
including congenital heart disease, conduction abnormalities, and
cardiomyopathy".
Atomoxetine (Strattera)
- A selective inhibitor of the presynaptic norepinephrine
transporter
- Increases both norepinephrine and dopamine levels,
especially in the prefrontal cortex
- Dosing: Start at 0.5 mg/kg/day and increase after 3-5d to
1.2-1.4 mg/kg/day. Can be given at bedtime or in divided dosages BID if
causes somnolence.
- Studies of efficacy:
- 297 pts 8-18yo with mod-severe ADHD randomized to
atomoxetine (at one of 3 doses; 0.5-1.8mg/kg/d divided BID) vs. placebo;
active-tx groups had sig. better improvement in ADHD sx at 8wks;
1.2mg/kg/d was as good as 1.8mg/kg/d (Peds. 108:E83, 2001--JW)
- 228 children w/ADHD randomized to atomoxetine vs.
methylphenidate (open-label); at 10wks, parent- and clinician-rated ADHD
sx were similar in both groups (Am. J. Psychiat. 159:1896, 2002--JW)
- Adverse effects:
- Two cases of severe hepatotoxicity reported early 2005; incidence of
that adverse effect unknown at that time
- Contraindications:
- MAO inhibitors within 15 days
- Narrow-angle glaucoma
- Use w/caution in presence of hypertension, tachycardia,
or urinary retention
Guanfacine (Intuniv)
-
1-4mg QD
-
For treatment of ADHD in pts > 6yo
-
A selective alpha-2A adrenergic agonist
-
Also used for hypertension
-
May cause hypotension, bradycardia, and/or syncope
Sources include: American Academy of Child and Adolescent Psychiatry guidelines:
Practice Parameter for the Assessment and Treatment of Children and Adolescents With Attention-Deficit/Hyperactivity Disorder. J. Am. Acad. Child
Adolesc. Psychiatry, 2007;46(7).