8.74: Attention-Deficit/Hyperactivity Disorder (ADHD)
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There has been a lot of debate over symptoms and what the name should be before it was decided to be called ADHD. William James referred to it as ‘explosive will’ and George Still called it ‘volitional inhibition’. ADHD has also been referred to as minimal brain dysfunction and hyperactive child syndrome. The DSM-II called it ‘hyper-kinetic reaction of childhood’, which was the first childhood disorder in the DSM. DSM-III referred to it as Attention Deficit Disorder (ADD) and it had much more information on it. It was classified as with or without hyperactivity. The DSM-IV calls it ADHD. DSM-V will also refer to it as ADHD.
There must be a persistent pattern of inattention and/or hyperactivity-impulsivity more severe and more frequent than in same-age peers. There has to be an onset of symptoms prior to seven years old, but diagnosis can occur much later. A child must display six or more symptoms of either inattention or hyperactivity-impulsivity for at least six months. Adults can have less. There must be some impairment from the symptoms present in two or more settings (e.g., at school/work and at home) and a clear impairment in social, school or work functioning. They symptoms cannot be accounted for by another mental disorder such as pervasive developmental disorder, schizophrenia, or any other psychotic disorder. The problems with inhibition (hyperactive-impulsive behavior) arise first, usually at ages 3-4, ahead of those related to inattention, with arise are 5-7 years old and then slow cognitive tempo arises at ages 8-10 (Mash & Barkley, 2003). Those with inattention are frequently diagnosed later in life due to the less disruptive nature of the problems. It will not go away with adulthood, but presentation does typically change.
- often does not give close attention to details or makes careless mistakes in schoolwork, work, or other activities.
- often has trouble keeping attention on tasks or play activities.
- often does not seem to listen when spoken to directly.
- often does not follow instructions and fails to finish schoolwork, chores, or duties in the workplace (not due to oppositional behavior or failure to understand instructions).
- often has trouble organizing activities.
- often avoids, dislikes, or does not want to do things that take a lot of mental effort for a long period of time (such as schoolwork or homework).
- often loses things needed for tasks and activities (e.g., toys, school assignments, pencils, books, or tools).
- often easily distracted.
- often forgetful in daily activities.
- inability to have sustained attention or persistence on tasks, remember and follow rules, and resist distractions (may be more related to working memory than true “attention” problems).
- exhibit more “off-task” time and less productivity (even occurs while watching television).
- slower and less likely to return to an activity once interrupted.
- less attentive to changes in the rules governing a task.
- less capable of shifting attention across tasks flexibly.
- often fidgets with hangs or feet or squirms in seat.
- often gets up from seat when remaining in seat is expected (such as in school).
- often runs about or climbs when and where it is not appropriate (adolescents or adults may feel very restless).
- often has trouble playing or enjoying leisure activities quietly.
- often “on the go” or often acts as if “driven by a motor”.
- often talks excessively.
- greater touching of objects.
- often blurts out answers before questions have been finished.
- often has trouble waiting one’s turn.
- often interrupts or intrudes on others (e.g., butts into conversations or games).
The 3 Subtypes
1. Combined type: if both criteria for inattentive and hyper-impulsive symptoms are met for the past 6 months. There must be 6 symptoms present from each. Combined is the most common of the subtypes.
2. Predominately Inattentive type: If criteria for inattentive is met but criterion for hyper-impulsive is not met for the past 6 months.
3. Predominantly Hyperactive-Impulsive type: If criterion for hyper-impulsive is met but criterion for inattentive is not met for the past 6 months.
Some say that the child is “just being a kid”. There is some level of all of the core symptoms is present in all children which is very normal. ADHD is separated from ordinary exuberance and “being a kid” by the degree of the symptoms and the impairment they cause.
Symptoms thresholds may not apply outside of 4-16 year old range. Fewer symptoms are needed to qualify for ADHD as age increases.
Appropriateness of item sets for different ages and genders. Inattention seems more geared for school-aged or adolescents. Hyper/Impulsive seems more applicable to younger children. This could influence the rates of diagnosis across age groups, resulting in more false-negatives as one gets older.
There is little if any research for the onset before age 7. No other mental disorder has this precise an age of onset. There is also no lower-age or IQ boundary in the DSM-IV-TR.
No research support for symptom duration of 6 months. There is some support for a 12 month period, though.
The requirement of impairment in 2/3 environments is situation specific and lacks parent-teacher agreement.
Some say that ADHD is not real and it is merely pathologizing normal behavior, which is not the case; research indicates that there are a large number of differences between ADHD and non-ADHD children.
The behavior of hyperactivity can be seen in 22-57% of children. Only 4.2-6.3% meet criteria for the action disorder, which is 5% nationwide. Parent-reports gives much lower figures than teacher-reports, which only seems to support the idea that environmental context is very important.
Males are 2.6-5.6 times more likely to be diagnosed as females within epidemiological samples; average ratio of 3:1. The clinic-referred samples have even higher ratios due to co-morbid Oppositional Defiant Disorder/Conduct Disorder seen in boys. This holds true even though research show that females have as great of functional impairments and deficits as the males.
Socioeconomic and cultural differences
There is little research on the relationship between socioeconomic status (SES) and ADHD rates. However, using the DSM criteria, there are higher rates of ADHD found outside the United States. This is most likely due to cultural differences in expectations or interpretations of symptoms. There are higher rates in the US reported for non-whites, yet they are from poorly controlled studies that had no correction for co-morbidity. It seems that ADHD occurs across all socioeconomic levels, although there are variations across all SES levels.
Co-morbid psychiatric disorders
There are high rates of co-morbidity in ADHD; 44% in community samples and 87% for clinic-referred samples. The most common of those disorders are Oppositional Defiant Disorder (54%-67%), Conduct Disorder (26% by adulthood), Antisocial Personality disorder (12-21%), learning disorders (30-50%), anxiety disorders 25% in childhood), and mood disorders (20-30%). Up to 18% of children may develop a motor tic in childhood (a symptom of Tourette’s), but this declines at a base rate of 2% by mid-adolescence and less than 1% by adulthood. Individuals with obsessive-compulsive disorder or Tourette’s disorder have a marked elevation in risk for ADHD, averaging 48% or more (Mash & Barkley, 2003).
- There are many concurrent developmental difficulties that are seen with ADHD:
- Physical problems: gross and fine motor control, motor sequencing.
- Working memory impairments
- Poor planning and anticipation
- lack of verbal fluency
- Inefficient self-monitoring
- Poor regulation of emotion
- Impaired academic functioning: the snowball effect-as you go on you get further behind. Between 19% and 26% of children with ADHD are likely to have any single type of learning disability, which, conservatively, is defined as a significant delay in reading, arithmetic, or spelling relative to intelligence and achievement in one of these three areas at or below the 7th percentile (Mash & Barkley, 2003).
- Reduced intelligence. These children often have lower scores on intelligence tests, especially in verbal intelligence, when compared to children without ADHD (Mash & Barkley, 2003).
- Poor social skills. Fellow classmates may not deem a child with ADHD as someone they would want to become friends with since they usually interrupt or join conversations without being invited into them. They are also seen as disruptive.
- Motor in-coordination: as many as 60% of children with ADHD, compared to up to 35% of normal children (Mash & Barkley, 2003).All of the listed impairments can fall under the domain of “executive functioning” since they are process that assist with self-regulation, behaviors that modify the probability of a subsequent behavior so as to change the probability of a later consequence. They are mediated by the prefrontal cortex.
Studies have concluded that children with ADHD are more accident-prone and get injured more often than children without the disorder. About 16% of a sample of hyperactive children from a study had at least four or more serious accidental injuries (broken bones, lacerations, head injuries, severe bruising, lost teeth, etc.), compared to the 5% of children in the control group (children without ADHD) (Mash & Barkley, 2003). Teenagers with ADHD have a higher frequency of vehicular crashes and a history of citations for speeding than children without ADHD (Mash & Barkley, 2003). This may be due to the inattention and/or hyperactive-impulsive behavior of a teenager with ADHD. Children with ADHD also have more sleep problems than a child without; they experience a longer amount of time to fall asleep, instability of sleep duration, tiredness at waking, or frequent waking during the night (Mash & Barkley, 2003).
ADHD arises from a combination of environmental, genetic, and neurological factors, meaning that there is no one true developmental pathway. Whatever pathway it takes, it often ends up disrupting prefrontal cortical-striatal network, which is smaller and less active in people with ADHD. Social factors may play a role in expression, but would not be purely responsible for this disorder.
Barkley’s model focuses on how behavioral disinhibition impacts four primary executive functions; poor working memory, delayed internalization of speech, immature regulation of affect/motivation/arousal, and impaired reconstruction. These impairments in executive function in turn impair social self-sufficiency. Barkley’s assumptions were; 1.) behavioral inhibition develops ahead of these four executive functions, 2.) each executive function emerges at different times and has a different developmental trajectory, 3.) ADHD impair the behavioral inhibition, which in turn impairs the executive function, 4.) deficit in behavioral inhibition is due to biological factors, 5.) deficits in self-regulation are caused by the primary behavioral inhibition, but in turn feedback to cause even poorer behavioral inhibition, and 6.) model does not apply to inattentive types of ADHD (this is the model’s biggest problem).
A typical battery for an ADHD assessment would include; a structured or semi-structured clinical interview that should cover developmental and family history, DSM-IV ADHD symptoms, and symptoms of typical co-morbid problems, intelligence and achievement testing to rule our learning disabilities since ADHD is highly co-morbid with them, parent, teacher and self-reports of behavior, and one could also use continuous performance measures but they have less diagnostic validity than parent or teacher report measures.
Medication is very effective at treating core symptoms. Central nervous system stimulants such as amphetamine and methylphenidate help in 70-80% of children. Another treatment is behavioral therapy, which cannot reduce the core symptoms, but it can help treat co-occurring problems such as; social skills training, parent training for oppositional behavior, helping parents shape home environment, working with teachers to shape school environment, etc. Behavioral therapy has the best long-term outcomes. A combination of medication and behavioral therapy has been found as most effective for longer-term outcomes No other treatments have been found to be effective. There are many out there that say they are, but they are basically aimed at taking people’s money such as changing diets, biofeedback and vitamins.
Changes proposed for DSM-5
DSM-5 changes the symptoms from inattention or hyperactivity and impulsivity to inattention and/or hyperactivity and impulsivity. There will also be more symptoms for hyperactivity and impulsivity added. Inattentive Presentation (Restrictive) will be added among the types of presentations of ADHD (American Psychiatric Association, 2010).
American Psychiatric Association. (2010). Proposed Draft Revisions to DSM Disorders and Criteria. Retrieved 2010, from DSM-5 Development: http://www.dsm5.org/ProposedRevisions/Pages/Default.aspx
Lack, C. W. (2010). Abnormal Psychology. Retrieved 2010, from Caleb W. Lack, Ph.D: http://www.caleblack.com/psy4753.html
Mash, E. J., & Barkley, R. A. (2003). Child Psychopathology (2 ed.). New York, NY: The Guilford Press.