ATTENTION-DEFICIT HYPERACTIVITY DISORDER (ADHD)
DEFINITION:
A neuropsychiatric disorder characterized by inattentiveness,
impulsiveness, and hyperactivity resulting in significant
im-pairment in functioning at home, school, or with peers.
EPIDEMIOLOGY:
- prevalence: 2.5% of children (ADHD)
- incidence: 1-6% of school-age children (ADD/ADHD)
- age of onset:
- before age 7 by definition
- risk factors:
- M > F (3-9:1); M = F (ADD)
- familial
- coexisting conditions
- oppositional defiant disorder (35%)
- conduct disorder (30-50%)
- language impairment (30%)
- anxiety disorder (25%)
- depression (25%)
- learning disability (20%)
- demoralization
- encopresis
- enuresis
- tic disorders (Tourette)
- substance abuse
DIFFERENTIAL DIAGNOSIS OF HYPERACTIVITY:
- acting out behaviour (due to emotional disturbance)
- age-appropriate overactivity
- Attention-Deficit Disorder (ADD)
- inadequate environmental parenting
- mental retardation
- mood disorder
- Pervasive Developmental Disorder
- primary learning disorder with secondary inattention
- specific medical disorders
- hearing-impairment
- lead toxicity
- hyperthyroidism
CLINICAL FEATURES (modified from DSM-IIIR):
- sometimes ADHD presents as part of a triad: ADHD, Tourette's
Syndrome, and oppositional conduct disorder
- the symptoms of ADHD and the comorbid conditions may change
as the patients age:
- wanders off alone
- inappropriate touching and handling objects
- trouble staying seated
- demands attention
- rapidly shifts from one activity to another
- sleep problems
- resists passive activities
2. Children/Adolescents
- difficult to be sedentary
- "antsy", fidgety, wound up
- uncomfortable with inactivity
- quick mood shifts (stimulus-related)
- poor self control
- non-reflective
- in the family history look for:
- childhood history of ADHD
- ADHD in partial remission
- substance abuse
- antisocial behaviour
- impulse control problems
2. Maternal History of:
INVESTIGATIONS:
- Stanford Binet
- Wechsler Intelligence Scale for Children-Revised
- Wisconsin Card Sort
2. Achievement
- Wide Range Achievement Test (WRAT)
- Woodcock/Johnson
2. Attention
- Conners rating scale
- Continuous performance task
- Porteus maze
3. Impulsivity
- Kagan's matching familiar figure test
4. Attention and Impulsivity
- Paired associated learning
- Choice reaction time tasks
2. Behaviour Rating Scales
- Yale Child Checklist
- Conners Teacher/Parent R.S.
- Child Behaviour Checklist (Teacher/Parent)
3. Imaging Studies
- focal hypoperfusion and diminished glucose use in the
premotor cortex and superior prefrontal cortex
2. CT (Head)
- if indicated, i.e., seizures (with EEG)
3. Evoked Potentials
4. Speech and Language Assessment
- if indicated, i.e., suspected communication problems
MANAGEMENT:
1. Diagnosis (Clinical)
- information from school, parents, other care-givers, etc.
- school records - cognitive test results
- teacher report - day-care report
- 8/14 criteria from DSM-IIIR
- secondary causes of hyperactivity ruled out
- behaviour is not due to an associated learning disability
or other condition (i.e., visual or auditory deficit)
- evidence that hyperactivity is pervasive and of a cognitive
impairment
2. Education
- counselling of parents and teacher
- review diagnosis, epidemiology, and prognosis
- a developmental handicap
- chonic in 60% of patients
- no treatment but symptoms can be successfully managed
- review management stratagies
- non-pharmalogical
- pharmalogical
- importance of follow-up
- remember that ADHD may be associated with significant
parental morbidity
- provide information in the form of books, videotapes,
hand-outs, support groups, etc.
3. Goals of Therapy
- to improve functioning at home, in school, and with peers
through the modification of the inattention, impulsiveness, and
hyperactivity
- to maximize cognitive functioning and social/behaviour
skills with minimal side effects
4. Non-Pharmacological Therapy
- using conditioning therapy, control of the enviroment, and
maximizing communication with the patient to restruc-ture the
types of demands placed upon the patient - mild cases may need
behavioural modification only without medical therapy
2. Psychotherapy
- individual or family therapy especially in those patients
with associated symptoms, i.e., conduct disorder
- - assist with coping strategies
5. Pharmacological Therapy
- drugs act to increase the probability of certain neuro-transmitters
(i.e., catecholamines) interacting with post-synaptic
receptors in certain areas of the brain
- 70% of patients will respond to the first stimulant, 70%
to the second stimulant and 70% to the third stimulant so that
the overall success rate on stimulants is >90% - low dosage
maximizes cognitive function, moderate dosage maximizes
social/behavioural skills, and high dosages increases the risk
for side effects while diminishing the effects on cognitive
functioning and social/behavioural skills
- long-acting stimulants may be used before the short-acting
stimulants to improve compliance
- use as first line medication in those with ADHD and ADHD
with a major affective component
- common side effects
- abdominal pain
- appetite suppression
- increased anxiety
- insomnia
- headaches
- loss of spontaneity
- mood change/irritability
- rebound phenomena
- picking of fingers
- tics
- contraindications to use
- hypersensitivity reaction
- assessment of effects
- parent and teacher ratings of cognitive functioning and
social/behavioural skills before therapy, during placebo,
and while medicated (at different dosages) also noting the
degree of side effects
- starting dose of 0.3 mg/kg/dose po bid and increasing to
a maximum of 0.7 mg/kg/dose if necessary - levels peak 1-2.5
hours postingestion with optimal therapeutic effect within 4
hours and lasting up to 7 hours
- effective in 75-80% of patients
- may attempt a discontinuation trial annually every
spring and/or drug holidays
2. Dextroamphetamine
- 0.15-0.5 mg/kg/dose po qid
3. Pemoline
- 0.8-0.9 mg/kg/dose po od
- moniter liver function tests as pemoline can cause a
hypersensitivity reaction involving the liver
2. Non-Stimulant Therapy
- indicated in those cases where stimulant therapy is
contra-indicated, ineffective, or cause adversity
- imipramine or desipramine
- add to stimulant therapy if tics become a problem
- side effects: arrhythmias (do a baseline ECG), sudden
death (desipramine)
- 70% response rate
2. Antipsychotic Agents
- Phenothiazines, Haloperidol, Lithium
3. Clonidine
- best to use the patch preparation
- improves social/behavioural skills but not cognitive
function
6. Prognosis
- 60% of children with ADHD are still symptomatic as young
adults and thus considered chronic
- risks in untreated patients - increased incidence of:
- aggressive behaviour - divorce
- anti-social personality disorder - school drop-out
- conduct disorder - substance abuse (59%)
- depression - thefts
- risk factors for non-compliance with medications:
- seen in 40-60% of patients
- older patient
- adolescent girls
- oppositional conduct disorder
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