Epidemiology
- 10% of children with ADHD have other learning disabilities
- ADHD is one of the most common childhood disorders and can continue through adolescence and into adulthood.
- The average age of onset is 7 years old. ADHD affects about 4.1% American adults age 18 years and older in a given year.
- The disorder affects 9.0% of American children age 13 to 18 years. Boys are four times at risk than girls. Studies show that the number of children being diagnosed with ADHD is increasing, but it is unclear why.
ADHD subtypes
- Predominantly hyperactive-impulsive
- Most symptoms (six or more) are in the hyperactivity-impulsivity categories.
- Fewer than six symptoms of inattention are present, although inattention may still be present to some degree.
- Predominantly inattentive
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- The majority of symptoms (six or more) are in the inattention category and fewer than six symptoms of hyperactivity-impulsivity are present, although hyperactivity-impulsivity may still be present to some degree.
- Children with this subtype are less likely to act out or have difficulties getting along with other children. They may sit quietly, but they are not paying attention to what they are doing. Therefore, the child may be overlooked, and parents and teachers may not notice that he or she has ADHD.
- Combined hyperactive-impulsive and inattentive
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- Six or more symptoms of inattention and six or more symptoms of hyperactivity-impulsivity are present.
- Most children have the combined type of ADHD.
Causes of ADHD
Scientists are not sure what causes ADHD, although many studies suggest that genes play a large role. Like many other illnesses, ADHD probably results from a combination of factors. In addition to genetics, researchers are looking at possible environmental factors, and are studying how brain injuries, nutrition, and the social environment might contribute to ADHD.
Genes. Results from several international studies of twins show that ADHD often runs in families. Researchers are looking at several genes that may make people more likely to develop the disorder. Knowing the genes involved may one day help researchers prevent the disorder before symptoms develop. Learning about specific genes could also lead to better treatments.
Children with ADHD who carry a particular version of a certain gene have thinner brain tissue in the areas of the brain associated with attention. This NIMH research showed that the difference was not permanent, however, and as children with this gene grew up, the brain developed to a normal level of thickness. Their ADHD symptoms also improved.
Environmental factors. Studies suggest a potential link between cigarette smoking and alcohol use during pregnancy and ADHD in children. In addition, preschoolers who are exposed to high levels of lead, which can sometimes be found in plumbing fixtures or paint in old buildings, may have a higher risk of developing ADHD.
Brain injuries. Children who have suffered a brain injury may show some behaviors similar to those of ADHD. However, only a small percentage of children with ADHD have suffered a traumatic brain injury.
Sugar. The idea that refined sugar causes ADHD or makes symptoms worse is popular, but more research discounts this theory than supports it. In one study, researchers gave children foods containing either sugar or a sugar substitute every other day. The children who received sugar showed no different behavior or learning capabilities than those who received the sugar substitute. Another study in which children were given higher than average amounts of sugar or sugar substitutes showed similar results.
In another study, children who were considered sugar-sensitive by their mothers were given the sugar substitute aspartame, also known as Nutrasweet. Although all the children got aspartame, half their mothers were told their children were given sugar, and the other half were told their children were given aspartame. The mothers who thought their children had gotten sugar rated them as more hyperactive than the other children and were more critical of their behavior, compared to mothers who thought their children received aspartame.
Food additives. Recent British research indicates a possible link between consumption of certain food additives like artificial colors or preservatives, and an increase in activity. Research is under way to confirm the findings and to learn more about how food additives may affect hyperactivity.
History taking
Inattention and Distractibility symptoms:
- Does the child listen to parents and teacher?
- Can s/he concentrate?
- Is the child easily distracted?
- Can he work without supervision?
- Is he able to finish the tasks in a timely manner?
- Dose he daydreams or looks confused most of the day?
Impulsivity symptoms:
- Does the child involve in risk taking behaviors?
- Can he wait for his turn?
- Does he constantly interrupt others?
- Does he react emotionally?
Hyperactivity/Overactivity components:
- Speech tone and pressure
- Amount of daily physical activity?
- Is the kid talkative?
Past medical history:
- Perinatal complications
- Developmental delay
- Endocrine disorders
- Oppositional Defiant Disorder
- Tourette’s Syndrome
- Sexual abuse history
Growth and development:
- Educational history
- Abuse
- Cruelty toward animals
- Involvement in criminal activities
- Substance abuse
Family History
- ADHD
- Conduct disorders
- Tick disorders
- Developmental disorders
- Substance use
Physical examination
- General appearance
- Interview with child
- Interview with parents and teacher
- Thyroid Examination
- Neurological exam
- Developmental milestones
- Hearing impairment
Associated features
- Academic failure
- Social problems
- Emotional instability
- School failure
- Poor planning, organization and task performance
- Speech and language problems
- Poor motor coordination
- Enuresis
- Insatiability
Differential Diagnosis
Conduct disorder
- Set fire
- Cruel to animals
- Lie
- Fighting repeatedly
- Stealing
- boys > girls
- hereditary
Oppositional defiant disorder
- hostile and defiant behavior against parents, teacher, …
- behaves normally around peers
- is not cruel to animals
- do not lie
- is not criminal
Mood disorder
Substance abuse
Antisocial disorder
Diagnostic work up
- TSH
- FBS
- Blood Lead level
Management
Non-Pharmacologic
- Goal setting for assignments and projects
- Educational Interventions for children with ADHD
- Educate the family and the school
- Counseling for parents and adolescent patients
- Family understanding (Coping)
Medication
- First line (if history of stimulant dependence):
- Bupropion (Wellbutrin)
- Second line (if history of stimulant dependence):
- Long acting stimulants such as (Concerta, Aptensio)
- First line (if no history of stimulant abuse):
- Methylphenidate LA (Ritalin LA)
- Amphetamine-Dextroamphetamine (Adderall XR)
- Methylphenidate (Concerta)
- Tomoxetine (Strattera) is a Non-stimulant agent (SNRI)
- Second line (if no history of stimulant abuse):
- SSRI if:
- Comorbid Major Depression
- Hyper-focused on activity (e.g. computer games)
- Obsessive-Compulsive type behavior
- Agents
- Bupropion (Wellbutrin)
- Venlafaxine (Effexor)
- TCAs for:
- Insomnia
- Enuresis
- Agents
- Imipramine
- Start 10 mg PO qhs (Up to 150 mg/day divided bid)
- Desipramine (Risk of sudden CV death)
- Start 10 mg PO qhs (Up to 150 mg/day divided bid)
- Imipramine
- SSRI if: