adhd

attention deficit hyperactivity disorder (ADHD)

introduction

  • AD/HD consists of a pattern of behavior that is present in multiple settings where it gives rise to social, educational or work performance difficulties
  • it is a developmental disorder and it would appear over 99% have symptom onset prior to 7yrs of age, and most fit the criteria before age 3 yrs, although recall of such symptoms in adult life can be poor with only 50% recalling symptoms prior to age 7yrs while 95% can recall symptoms prior to age 12 years
  • it is now regarded as a persistent neurodevelopmental disorder impairing executive functioning (EF), or the “management system” of the brain, that usually persists into adulthood and can be an important co-morbid factor in adult pyschiatric illnesses and substance abuse
  • it is estimated to affect 3-5% of children.

evolution of the diagnostic criteria

  • 1st evidence of documention was in 1775 by Melchior Adam Weikard, a prominent German physician
  • the treatment of children with similar behavioral problems who had survived the epidemic of encephalitis lethargica from 1917 to 1918 and the pandemic of influenza from 1919 to 1920 led to terminology which referred to “brain damage” although this was later removed when it was realised many had this condition without evidence of brain damage.
  • DSM-II (1968) it was the “Hyperkinetic Reaction of Childhood”
  • research in the 1970s and 1980s began to show there are different types of attention deficit
  • DSM-III (1980) “ADD (Attention-Deficit Disorder) with or without hyperactivity” was introduced and specified a maximum age for its onset
    • DSM-III radically changed classifications systems by favoring diagnostic reliability over theoretical explanations
  • in 1987 this was changed to ADHD in the DSM-III-R
  • DSM IV (1994) introduced ADHD with sub-types and added the criteria that impairment must be present prior to age 7 yrs not just symptoms
  • ICD-10 came into use 1994 after being ratified in 1990
  • DSM V (2012 proposed) changed sub-types to “presentations” and increased age cut-off from 7yrs to 12yrs while changing age cut-off criteria from impairment to symptoms. These changes will thus increase the prevalence as it is more inclusive.

associations and sequeleae

  • many also have autism spectrum disorder (ASD) in childhood hence the proposed removal of PDD from the exclusion criteria for DSM-V
  • disruptive behaviour
  • learning difficulties
  • classroom disruption
  • difficulty in maintaining friendships

adult sequelae

  • persistence of ADHD symptoms into adulthood varies:
    • 15% retain full ADHD status
    • 65% in partial remission
    • 20% in full remission
  • adult symptoms usually relate to distractibility, impulsiveness, poor concentration, inability to persist at tasks, and difficulties with working memory, organization, and planning. 1)
    • often easily distracted by extraneous stimuli or irrelevant thoughts
    • often makes decisions impulsively
    • often has difficulty stopping activities or behaviors when they should do so
    • often starts a project or task without reading or listening to the directions carefully
    • often shows poor follow-through on promises or commitments made to others
    • often has trouble doing things in their proper order or sequence
    • often more likely to drive a motor vehicle much faster than others
    • often has difficulty engaging in leisure activities or doing fun things quietly
    • often has difficulty sustaining attention in tasks or play activities
    • often has difficulty organizing tasks and activities
    • significant impairment in social, educational, domestic (eg, dating, marriage, cohabitation, financial, driving, childrearing), occupational, or community functioning 2)
  • 40-60% of adolescents with ADHD and 24-35% of clinically referred adults with criteria for ADHD also meeting criteria for Oppositional Defiant Disorder (ODD) and up to 25% meeting criteria for Conduct Disorder
  • many develop Antisocial Personality Disorder with higher risk of Substance Use Disorder (at least 2x the risk of adults without ADHD).
  • ~25% of adults with drug dependence meet the ADHD criteria
  • ~20% of adults with bipolar disorder, dysthymia or agoraphobia meet the ADHD criteria
  • 13% of adults with social phobia or post-traumatic stress disorder meet the ADHD criteria

proposed DSM V criteria

  • age cut off increased to 12 years and only requires symptoms not impairment
  • “sub-types” changed to “presentations” in an attempt to make the classification more stable for an individual as it became evident that HT subtype children generally migrated to CT subtype as school demands increased.
  • 4th “presentation added “restrictive”
  • item E has been modified to remove PDD

A

  • two main diagnostic axes: either A1 and/or A2

A1. Inattention

Six (or more) of the following symptoms have persisted for at least 6 months to a degree that is inconsistent with developmental level and that impact directly on social and academic/occupational activities.

  • a. Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or during other activities (e.g., overlooks or misses details, work is inaccurate).
  • b. Often has difficulty sustaining attention in tasks or play activities (e.g., has difficulty remaining focused during lectures, conversations, or reading lengthy writings).
  • c. Often does not seem to listen when spoken to directly (e.g., mind seems elsewhere, even in the absence of any obvious distraction).
  • d. Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., starts tasks but quickly loses focus and is easily sidetracked; fails to finish schoolwork, household chores, or tasks in the workplace).
  • e. Often has difficulty organizing tasks and activities (e.g., difficulty managing sequential tasks; difficulty keeping materials and belongings in order; messy, disorganized, work; poor time management; tends to fail to meet deadlines).
  • f. Often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort (e.g., schoolwork or homework; for older adolescents and adults, preparing reports, completing forms, or reviewing lengthy papers).
  • g. Often loses things necessary for tasks or activities (e.g., school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, or mobile telephones).
  • h. Is often easily distracted by extraneous stimuli (for older adolescents and adults, may include unrelated thoughts).
  • i. Is often forgetful in daily activities (e.g., chores, running errands; for older adolescents and adults, returning calls, paying bills, keeping appointments).

A2. Hyperactivity and Impulsivity

Six (or more) of the following symptoms have persisted for at least 6 months to a degree that is inconsistent with developmental level and that impact directly on social and academic/occupational activities.

hyperactivity
  • a. Often fidgets with or taps hands or feet or squirms in seat.
  • b. Often leaves seat in situations when remaining seated is expected (e.g., leaves his or her place in the classroom, office or other workplace, or in other situations that require remaining seated).
  • c. Often runs about or climbs in situations where it is inappropriate. (In adolescents or adults, may be limited to feeling restless).
  • d. Often unable to play or engage in leisure activities quietly.
  • e. Is often “on the go,” acting as if “driven by a motor” (e.g., is unable or uncomfortable being still for an extended time, as in restaurants, meetings, etc; may be experienced by others as being restless and difficult to keep up with).
  • f. Often talks excessively.
impulsivity
  • g. Often blurts out an answer before a question has been completed (e.g., completes people’s sentences and “jumps the gun” in conversations, cannot wait for next turn in conversation).
  • h. Often has difficulty waiting his or her turn (e.g., while waiting in line).
  • i. Often interrupts or intrudes on others (e.g., butts into conversations, games, or activities; may start using other people’s things without asking or receiving permission, adolescents or adults may intrude into or take over what others are doing).

B

Several inattentive or hyperactive-impulsive symptoms were present prior to age 12. (in DSM IV the age criteria was 7 years, and evidence of impairment was required)

  • over 96% of cases are captured by age 12-14 yr cut-off
  • as adults, only 50% can recall what they were like before age 7yrs while 95% can recall behaviour prior to 12 years
  • age 7yrs had no validity and excluded valid cases
  • the DSM IV additional criteria of requiring impairment had little evidence to support it
  • this criteria only requiring symptoms and not impairment is more consistent with ICD, and a requirement for impairment would create issues with assessment of this, and variation of school standards
  • in the study by Applegate et al in 1997, whilst nearly all youths who met symptom criteria for HT also met the impairment criteria before age 7yrs, only 18% of those with CT and 43% of those with IT did so.

C

Criteria for the disorder are met in two or more settings (e.g., at home, school or work, with friends or relatives, or in other activities).

D

There must be clear evidence that the symptoms interfere with or reduce the quality of social, academic, or occupational functioning.

E

The symptoms do not occur exclusively during the course of schizophrenia or another psychotic disorder and are not better accounted for by another mental disorder (e.g., mood disorder, anxiety disorder, dissociative disorder, or a personality disorder).

  • the wording in DSM IV was:
    • “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).”

Specify Based on Current Presentation

Combined Presentation:

  • If both Criterion A1 (Inattention) and Criterion A2 (Hyperactivity-Impulsivity) are met for the past 6 months.
  • formerly Combined Type (CT)

Predominantly Inattentive Presentation:

  • If Criterion A1 (Inattention) is met but Criterion A2 (Hyperactivity-Impulsivity) is not met and 3 or more symptoms from Criterion A2 have been present for the past 6 months.
  • formerly Predominantly Inattentive Type (IT)

Inattentive Presentation (Restrictive):

  • If Criterion A1 (Inattention) is met but no more than 2 symptoms from Criterion A2 (Hyperactivity-Impulsivity) have been present for the past 6 months.
  • NB. this option is new in DSM V

Predominantly Hyperactive/Impulsive Presentation:

  • If Criterion A2 (Hyperactivity-Impulsivity) is met and Criterion A1 (Inattention) is not met for the past 6 months.
  • formerly Predominantly Hyperactive/Impulsive Type (HT)
    • almost all the cases of HT in the field trials were found in 4-6 year olds
    • the DSM-IV Work Group decided that young children who met criteria for HT likely shift to CT as increasing demands of school make their attention problems evident.3)

pharmacologic Rx

Australian PBS approved medications for Rx of ADHD

  • dexamphetamine
  • clonidine (Catapres®), an alpha-2 noradrenergic agonist, is sometimes prescribed to reduce persisting aggression and hyperactivity in children with ADHD, or for children with ADHD who are experiencing sleep disturbances.
  • Ritalin®, a short-acting methylphenidate was added in August 2005
  • Attenta®, a cheaper short-acting methylphenidate formulation was added in December 2005 but discontinued in November 2008
  • Concerta®, an extended release formulation of methylphenidate was added in April 2007
  • Strattera®, atomoxetine, is the only non-stimulant medication approved for ADHD and was listed on PBS July 2007
  • Ritalin LA®, an extended release formulation of methylphenidate was added in April 2008
  • NB. authority for the extended release forms is only available to those between 6-18 yrs age, whilst authority of the short-acting formulations are subject to prescription in accordance with local State/Territorial laws.
1)
Barkley RA. Murphy KF, Fischer M. Identifying new symptoms for ADHD in adulthood. In: ADHD in Adults: What the Science Tells Us New York, NY: Guilford Press; 2008:170-
2)
Barkley and Brown, 2008
adhd.txt · Last modified: 2012/09/02 10:47 by gary1