|
 Nazir Kayali MD. FAAP.
Attention-deficit/hyperactivity disorder ADHD
- is the most common neurobehavioral disorder of childhood
- One of the most prevalent chronic health condition affecting school-aged children
- The most extensively studied mental disorder of childhood
Epidemiology
- Studies of the prevalence of ADHD across the globe have generally reported that 5-10% of school-aged children are affected.
- although rates vary considerably by country, perhaps in part due to differing sampling and testing techniques.
- The prevalence rate in adolescent samples is 2-6%.
- Approximately 2% of adults have ADHD
- ADHD is often underdiagnosed in children and adolescents.
- Youth with ADHD are often undertreated with respect to what is known about the needed and appropriate doses of medications.
PATHOGENESIS
- Functional MRI findings suggest
1- low blood flow to the striatum.
2- a smaller brain volumes of specific structures, such as the prefrontal cortex and basal ganglia. Children with ADHD have approximately a 5-10% reduction in these brain structures.
- The prefrontal cortex and basal ganglia are rich in dopamine receptors.
- This knowledge, plus data about the dopaminergic mechanisms of action of medication treatment for ADHD, has led to the dopamine hypothesis, which postulates that disturbances in the dopamine system may be related to the onset of ADHD
ETIOLOGY
- Multiple factors have been implicated in the etiology of ADHD.
- many unknowns
ETIOLOGY / genetic
- There appears to be a strong genetic component to ADHD
- family history of ADHD, alcoholism, sociopathy, mood and anxiety disorders
- It was found that over 25% of the first-degree relatives of the families of ADHD children also had ADHD, whereas this rate was only about 5% in each of the control groups.
- Therefore, if a child has ADHD there is a five-fold increase in the risk to other family members.
- Approximately half of parents who have been diagnosed with ADHD themselves, will have a child with the disorder.
- They reported an 82 percent concordance rate for ADHD in identical twins as compared to a 38 percent concordance rate for ADHD in non-identical twins.
ETIOLOGY / Medical
- Mothers of children with ADHD are more likely to experience birth complications, such as toxemia, lengthy labor, and complicated delivery.
- children with severe traumatic brain injury are reported to have subsequent onset of substantial symptoms of impulsivity and inattention.
- CNS infections
ETIOLOGY / Exposure
- Exposure to toxins, such as maternal smoking or alcohol use and postnatal exposure to lead, has also traditionally been correlated with ADHD
- In a study that assessed hyperactivity behaviors, 297 3-9 year-old were given drinks containing either placebo or artificial food coloring mixes. Children who received the artificially colored beverages had statistically significant hyperactivity scores.
- only some hyperactive children would respond favorably to elimination
ETIOLOGY / Psychosocial
- family stressors may also contribute to or exacerbate the symptoms of ADHD.
ETIOLOGY / Cultural
much lower prevalence estimates in Europe and Japan than US
CLINICAL MANIFESTATIONS
Diagnosis
CLINICAL MANIFESTATIONS
Three Sub-Types of ADHD
- Predominantly hyperactive type
- Predominantly inattentive type
- Mixed Type
Diagnosis:
- Parent interview is core assessment
- Obtain academic, behavioral, psychoeducational testing, and attendance reports from school
- Use parent and teacher rating scales (when possible)
- Complete medical history and physical examination
- Evaluate for comorbidity
Diagnosis
According to the 4th edition of the American Psychiatric Association's Diagnostic and Statistical Manual (DSM-IV), ADHD is characterized by:
(1) inattention, including increased distractibility and difficulty sustaining attention
(2) poor impulse control and decreased self-inhibitory capacity
(3) motor overactivity and motor restlessness
DSM-IV diagnostic criteria for ADHD (American Psychiatric Association's diagnostic and statistical manual):
1- Developmentally inappropriate levels of inattention, hyperactivity, and impulsivity that begin in childhood and
2- cause impairment in school performance, intellectual functioning, social skills, driving, and occupational functioning
3– onset <7 years of age (childhood onset)
4– disturbance lasting >6 month
5– cross-situational (home, school, work)
6- Symptoms do not occur exclusively during the course of a pervasive developmental disorder (PDD), schizophrenia, or other psychotic disorder
7- must not be secondary to another disorder (e.g., mood disorder, anxiety disorder, dissociative disorder, personality disorder)
Diagnosis / Inattention
Six (or more) of the following symptoms:
Diagnosis / Inattention
1- Often fails to give close attention to details or makes careless mistakes in schoolwork, work, or other activities
2- Often has difficulty sustaining attention in tasks or play activities
3- Often does not seem to listen when spoken to directly
4- 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)
5- Often has difficulty organizing tasks and activities
6- Often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort (such as schoolwork or homework)
7- Often loses things necessary for tasks or activities (e.g., toys, school assignments, pencils, books, tools)
8- Is often easily distracted by extraneous stimuli
9- Is often forgetful in daily activities
Diagnosis / Hyperactivity
Six (or more) of the following symptoms of hyperactivity-impulsivity:
1- Often fidgets with hands or feet or squirms in seat
2- Often leaves seat in classroom or in other situations in which remaining seated is expected
3- 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)
4- Often has difficulty playing or engaging in leisure activities quietly
5- Is often "on the go" or often acts as if "driven by a motor"
6- Often talks excessively
Impulsivity
7- Often blurts out answers before questions have been completed
8- Often has difficulty awaiting turn
9- Often interrupts or intrudes on others (e.g., butts into conversations or games)
Differential Diagnosis
1- Chronic illnesses (migraine headaches, absence seizures, asthma and allergies, hematologic disorders, diabetes, childhood cancer, itch) affect up to 20% of children in the U.S.
2- substance abuse may result in declining school performance and inattentive behavior.
3- Sleep disorders, including those secondary to chronic upper airway obstruction from enlarged tonsils and adenoids, frequently result in behavioral and emotional symptoms
4- Depression and anxiety disorders may cause many of the same symptoms as ADHD but, may also be comorbid conditions.
5- Obsessive-compulsive disorder may mimic ADHD, particularly when recurrent and persistent thoughts, impulses, or images are intrusive and interfere with normal daily activities
6- Adjustment disorders secondary to major life stresses or parent-child relationship disorders
7- Vision and hearing problems
8- Developmental or learning problems; language deficits
Comorbidity
The National Institute of Mental Health reported that:
1) 15-25% of children with ADHD also have learning disabilities
2) 30-35% also have language disorders
3) 15-20% are also diagnosed with mood disorders
4) 20-25% have coexisting anxiety disorders
5) Also many associated medical issues: tics, seizure disorder, etc
TREATMENT:
- Psychosocial Treatments
- Behavior management
- Medications
Treatment \ Psychosocial
- the parents and child should be educated with regard to the ways in which ADHD can affect learning, behavior, self-esteem, social skills, and family function.
- The clinician should set goals for the family to improve the child's interpersonal relationships, develop study skills, and decrease disruptive behaviors.
TREATMENT \ Behavior management
- The goal of such treatment is for the clinician to identify targeted behaviors that cause impairment in the child's life
- and for the child to work on progressively improving his or her skill in these areas.
- The clinician should guide the parents and teachers in implementing rules, consequences, and rewards to encourage desired behaviors.
TREATMENT
- Psychosocial Treatments
- Behavior management
- Medications
Which Treatment Is Best for ADHD?
- 540 children with ADHD for 24 months
- Medication alone was superior to all other treatments and equivalent or superior to any combination
- Behavior management was inferior to medication
- Although no improvement in performance was found with combined medication and behavior therapy, parents liked the addition of behavior therapy.
TREATMENT / Medications:
The most widely researched medications used in the treatment of ADHD are the psychostimulant medications, including
- methylphenidate
- amphetamine, and/or various dextroamphetamine preparations
TREATMENT / Psychostimulants
Methylphenidate (MPH) and Mixed Amphetamine Salts (MAS)
- Remain treatment of choice
- Similar mechanism of action
- Slow reuptake of DA and NE
- MAS also release more NE
TREATMENT methylphenidate compunds
- Ritalin
- Focalin, Focalin XR (d-MPH)
- Concerta (OROS-MPH)
- Metadate CD (biphasic), ER (extended)
- Ritalin LA (biphasic release)
- Ritalin SR (extended release)
- Methylin (liquid)
- Daytrana (transdermal MPH patch)
TREATMENT Amphetamine salts compounds
- Adderall
- Adderall XR
- Vyvanse (prodrug of Adderall XR)
- Dextroamphetamine (dexedrine)
|
