Attention Deficit Hyperactivity Disorder (ADHD)

Overview
Diagnostic criteria
ADHD subtypes
How ADHD is assessed/diagnosed
What causes ADHD?
Treatment
Recommended reading

ADHD overview

When one hears the acronym ADHD, it stereotypically brings to mind a child of grade school age, usually a boy, who is hyperactive, non-compliant, and out of control. We seldom hear about those children who are not hyperactive but still meet criteria for ADHD because of severe difficulties in focusing, concentrating, or paying attention. We also do not hear much about the significant number of adults who struggle with ADHD. The following paragraphs aim to guide the reader through the facts of ADHD, including how it is diagnosed in Nova Scotia and what routes to take if you or someone you care for has an actual or suspected diagnosis of ADHD.

Prevalence and gender effects

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder with core features of inattention, hyperactivity, and impulsivity. It is estimated to occur in 5-10% of school aged children1 and affects about 4% of adults,2 making it one of the most prevalent mental health problems at any age. This also highlights the fact that most persons diagnosed with ADHD still meet criteria in adulthood; it is not something that children will typically ‘grow out of.’

Although boys represent 75% of ADHD diagnoses, it has been suggested that girls are likely underdiagnosed.3 This may be due to the greater likelihood of boys being identified and referred due to associated behavioral problems. To illustrate, boys who are referred to a clinic with ADHD symptoms, are more likely to meet additional criteria for diagnoses of Oppositional Defiant Disorder (ODD) or Conduct Disorder (CD), which on their own, are more common in boys.4 In comparison, Girls who are referred to a clinic with ADHD symptoms, are more likely to have significant social problems.5 A recent study found no gender differences in associated problems among non-referred children and adolescents with ADHD.6 In other words, boys and girls may not differ in terms of meeting ADHD criteria, but rather their associated problems, which makes it easier to identify and help boys who are struggling more generally. If girls are in general, less likely to have obvious 'acting out' or behavioral problems, those with ADHD are less likely to get identified, referred, diagnosed, and helped.

Diagnostic Criteria for ADHD

Although previously called Attention Deficit Disorder (ADD), particularly in cases involving few signs of hyperactivity, the proper terminology is ADHD, which accounts for several subtypes of the disorder and involves the three main components: inattention, hyperactivity, and impulsivity.

Diagnostic criteria according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV),4 are as follows:

Inattention (6 or more):

Often:
1. fails to give close attention to details or makes careless mistakes
2. has difficulty sustaining attention in tasks or play activities
3. does not seem to listen when spoken to directly
4. does not follow through on instructions and fails to finish work, chores, or duties
5. has difficulty organizing tasks or activities
6. avoids/dislikes/is reluctant to engage in activities requiring sustained mental effort
7. looses things necessary for tasks or activities
8. is easily distracted by extraneous stimuli
9. is forgetful in daily activities

Hyperactivity-Impulsivity (6 or more):

Hyperactivity
Often:
1. fidgets with hands or feet or squirms in seat
2. leaves seat in situations where remaining in seat is expected
3. runs about or climbs excessively during inappropriate situations
4. has difficulty playing or engaging in leisure activities quietly
5. is “on the go” or often acts as if “driven by a motor”
6. talks excessively

Impulsivity
Often:
1. blurts out answers before questions have been completed
2. has difficulty awaiting turn
3. interrupts or intrudes on others

In addition to the above:

symptoms must persist for 6 months and must be to a degree considered maladaptive and developmentally inappropriate.
symptoms must produce clinically significant impairment in social, academic, or occupational functioning.
some symptoms/impairment must have been present before age 7 years.
some symptoms/impairment must be present in two or more settings.

ADHD subtypes

Based on the diagnostic criteria, several subtypes of ADHD can be identified. Below are the sub-types as outlined in the DSM-IV.4

Diagnosis of ADHD, Predominantly Hyperactive-Impulsive Type:

This involves a diagnosis meeting “Hyperactivity-Impulsivity” criteria, but not those for “Inattention.” It is the least common form of ADHD.

Diagnosis of ADHD, Predominantly Inattentive Type:

This involves a diagnosis meeting “Inattention” criteria, but not those for “Hyperactivity-Impulsivity.” It is not as common or as researched as the combined type of ADHD (below). It often does not fit the stereotypical ADHD child, and for that reason may go unnoticed or undiagnosed. This may be due to the fact that the without the more behaviorally obvious and potentially disruptive hyperactivity-impulsivity, it is less noticeable, although no less serious. Children of this type are not hyperactive and may actually present as hypoactive, appearing somewhat slowed or sluggish motorically and mentally.7

Diagnosis of ADHD, Combined Type:

ADHD, Combined Type, involves a diagnosis meeting criteria for both “Inattention” and “Hyperactivity-Impulsivity.” It is the most common sub-type of ADHD and has been researched extensively. Most of the information you will find on ADHD is based on this subtype.

How ADHD is assessed & diagnosed

Although ADHD diagnostic criteria seem quite straightforward in the DSM-IV, there is still much subjectivity in endorsing items in the above list and much debate about how a formal diagnosis should be made. The issue is compounded even more by accusations that health professionals hand out ADHD diagnoses all too readily.

In Nova Scotia, ADHD symptoms are typically assessed through consultation with a health professional and by using some sort of "behavioral report checklist," usually adapted from the diagnostic criteria above and filled out by a parent and teacher. This "dual rater" method can therefore test the requirement of symptoms being present in two or more settings.

One major criticism of this method is that the standards are based on subjective criteria alone. Put plainly, a diagnosis is made by a health professional who base their clinical judgment on historical information described by the parent and the combined subjective opinions of parent and teacher. Even if these sources of information were capable of providing accurate descriptions of the child's behavior, they are not necessarily free from bias. Parents may unknowingly exaggerate the extent of behavioral problems in an honest attempt to get help for their struggling child. Similarly, teachers may strongly endorse items that indicate a problem because they know that a child needs help, and with a diagnosis, they will be more likely to get it. While this sort of reporting may lead to a diagnosis, it could be the wrong one.

Another criticism of this method involves looking at the 'behavioral-checklists' themselves. Most of the questions or items will look similar to this:

"leaves seat in situations where remaining in seat is expected"

Not True At All
Just A Little True
Pretty Much True
Very Much True

Notice that the responses have no mention of objective criteria (i.e. "leaves seat 2-4 times per day"); the 'rater' (parent or teacher) must interpret for themselves how often the behavior should be seen for it to be "Pretty Much True." Subjective opinion therefore becomes even more subjective and much less scientific.

If we look at the research behind these 'behavioral report measures,' the situation becomes even more worrisome. A recent 2006 review of ADHD behavior rating scales found that many of the scales commonly used in clinical practice today are not adequately validated and supporting data are based on poor research with major design flaws.8 Even those behavioral report measures evaluated by more stringent research standards were found to accurately diagnose ADHD only 69% of the time.

In general, behavioral report measures have higher sensitivity than specificity. In other words, they tend to be minimally sufficient at identifying true and distinct cases of ADHD, but poor at distinguishing true ADHD from other types of problems that have similar symptoms (i.e. conduct disorder, learning disabilities, neurodevelopmental disorders, etc.).9 10 With ADHD having such high rates of co-occurring diagnoses, this is not encouraging news. But clinicians who recognize these weaknesses are often willing to provide more comprehensive assessments.

A comprehensive ADHD assessment

The stakes are very high for a child with a pending ADHD diagnosis. An informed assessment and diagnosis can get assistance, school support, and if necessary, prescription medication. Alternatively, a poor assessment could miss important factors masking as ADHD and might have your child on unnecessary medications for which there is little research pertaining to long-term safety and effectiveness.

At minimum, an ADHD assessment should additionally assess for problems that can co-occur with, or be mistaken for, ADHD. This means assessment of learning, memory, and screening for psychosocial problems. By doing this kind of assessment, one might at least rule in/out these relatively common overlapping issues.

But even after widening the assessment scope, one is still dealing with the issue of subjectivity and the concerns noted above in assessing ADHD symptoms. Some clinicians choose to overcome this dilemma by adding more objective testing to a typical assessment. This means administering standardized tests to the child/adolescent so that their performance can be compared to that of a typical child of the same age and sex. These objective tests may include measures of attention/concentration and Executive Function, which is an umbrella term that includes divided/sustained attention, working memory, planning, organization, and the ability to monitor one's own behavior. Most children with ADHD will exhibit problems in Executive Function,11 12 though few clinicians explicitly assess it. Objective testing has been shown to improve the accuracy of ADHD diagnoses and provide a wealth of additional information that can be used for treatment planning.13 This last part is important, because ADHD children can have very different underlying deficits and a diagnosis of ADHD is not very helpful for treatment planning. Specific information about a child's unique and individual needs can be used to develop individually tailored interventions that are more likely to be useful. Current research also suggests that the various types of ADHD (discussed below), involve different parts of the brain, and may respond differentially to medication.11 If a comprehensive assessment is able to more accurately pin-point specific underlying deficits or types of ADHD, this information could be potentially useful to physicians treating children who need medication.

In summary, a good comprehensive assessment is the most important starting point. If you take the time to investigate and ask the right questions, you will find some good clinicians doing these sorts of comprehensive assessments. Consider it an investment.

Is ADHD over-diagnosed?

Although public and media conceptions often reflect a concern that ADHD is over-diagnosed, a recent 2007 review of the research data suggests that these concerns are unwarranted.14 The results from this review suggest that while ADHD is frequently misdiagnosed, it does not appear to be over-diagnosed.

Common co-occurring conditions15

Children diagnosed with ADHD are more likely to face additional problems:

Oppositional Defiant Disorder (ODD) 54-67%
Conduct Disorder (CD) 20-50%
Learning Disabilities 19-26%
Mood Disorders 20-30%
Anxiety Disorders 10-40%
Substance Use Disorders 12-24%
50-80% of children diagnosed with ADHD will continue to meet criteria into adolescence, though severity of symptoms will typically decline

Although there is some debate as to whether these comorbid disorders are actually separate disorders or are caused by ADHD symptoms, clinical ‘best practice’ advice suggests that they should be treated as simultaneous, but separate problems.

What Causes ADHD?

As stated above, ADHD is best considered an umbrella term describing problems of attention/concentration, Executive Functioning, and self-regulation in general. All of these concerns seemingly point to something going on in the frontal-subcortical systems of the brain.3 Physiological evidence has been consistent in supporting this idea, with findings of reduced brain volume and decreased brain activation in these areas compared to same age non-ADHD peers.3 At a pharmacological level, a great deal of evidence additionally implicates dysfunctional levels of catecholamines (i.e. dopamine & norepinephrine), which are thought to be important neurotransmitters in regulating attention, concentration, and response inhibition.16 Most ADHD medications are thought to be effective by altering these levels.

At present, the best causal explanation is one of multiple pathways and influences. Unfortunately, public perceptions do not reflect the ever growing understanding of these various causal pathways. For example, a recent 2007 study found that the average parent has relatively poor knowledge of ADHD.17 Specifically, 52% of all parents surveyed believed that ADHD is the result of parental spoiling. Only 6.2% believed that ADHD difficulties would persist for the whole life, which from the discussion above, does not appear true.

While the research suggests that one might 'acquire' ADHD by being exposed to risk factors including: maternal exposure to risk factors (i.e. smoking/drinking during pregnancy); problems during labor, delivery, & neonatal period (i.e. premature/low birth-weight); early developmental and neurological problems;18 and traumatic brain injury,19 these circumstances appear to represent a minority of cases. ADHD appears in most cases to be inherited rather than 'acquired.' Research investigating causal mechanisms has estimated that 91% of ADHD symptoms can be explained by genetic rather than environmental factors.20 While environmental factors (i.e. parenting style) may influence the severity of ADHD symptoms, parents should understand that this is primarily a disorder of biological origin and they are in no way to blame.

Treatment

So far, we have discussed what is going on behaviorally, and briefly, what the research suggests is going on neurophysiologically (i.e. in the brain) among those diagnosed with ADHD. In truth, they are almost certainly two sides of the same coin; our biology (i.e. genetics, neurochemistry, etc.) influences our thoughts, behavior and feelings, and the opposite is just as likely. That is, our environment can influence the expression of that biology and even brain development. It therefore makes sense that we consider two different approaches to treatment.

Treatment for ADHD typically involves medication and/or some kind of behavioral or psychosocial intervention. Most research suggests that in general, medication alone is better than behavioral interventions alone with the combination of the two having the most success.21 22 The combined "medication + behavioral therapy" treatment method often allows children to be treated successfully with lower doses of medicine, compared to those treated with medication alone. While some children respond well to behavioral interventions and may not need medication, most research points to the need for both, which ideally involves good collaboration between physician and psychologist. A physician might prescribe and monitor medications, while the psychologist would be involved in psychosocial interventions.

Medication

Even if you are thoroughly against putting your child on medication, a diagnosis of ADHD should at least warrant a thoughtful consult with a physician. Medications have been used to treat ADHD for decades and the class of drugs most commonly used are categorized as 'stimulants.' These medications have been shown to be very effective for treating the core symptoms of inattention, overactivity, and impulsivity, with less evidence for changes in social skills, achievement, family functioning, internalizing symptoms (i.e. low self-esteem & anxiety).23

In general, these treatments have been shown to be relatively safe and effective after 2 years of continued treatment, but additional research is needed to determine long-term efficacy and safety.23 Side effects are not uncommon, but are typically mild. They may include: delayed sleep onset, reduced appetite, abdominal pain, weight loss, tics, jitteriness, headaches, anxiety, irritability, and sadness.24 The severity of side effects is often related to dosage, so it is important to discuss these issues with the monitoring physician. In addition, some people will find satisfactory results from one medication, others from another. Finding the right medication and effective dose may take some time. To help your prescribing physician, it is recommended that you keep a journal for logging ADHD symptoms or additional symptoms and side effects. Overall, these medications are believed to be safe and the minimal risks associated with them are often outweighed by their effectiveness in helping those whose life is significantly affected by ADHD.

Psychosocial Intervention

While there is no apparent 'cure' for ADHD, years of research and clinical studies have shown that behavioral approaches are useful in managing ADHD symptoms.22 A behavioral approach essentially means developing a program for 'tweaking' the environment according to how your child learns, thereby enhancing the possibility for success. For example, in a school setting, a typical ADHD child will do better sitting at the front of the class and away from doors, windows, and talkative children, which could serve as easy distractions. At home and school, 'behavioral charting' can also be quite effective, where children can work towards smaller short-term behavioral goals for stickers or rewards.

Due to deficits in Executive Functioning, most children with ADHD need help planning and organizing. Schedules and routines are very important, and children will benefit a great deal from knowing what to expect and having greater organization (i.e. colour coded binders for school or a quiet and tidy place to do homework). Children with ADHD are also likely to benefit from consistent rules that they can understand and follow; small and frequent rewards work best for following the rules. Since many of these children are prone to getting in trouble and receiving criticism, parents and teachers should look for good behavior and praise it often.

The key to developing successful behavioral interventions begins with a comprehensive assessment. Again, not all ADHD children are alike, the more information one has about a child's strengths and weaknesses, the better equipped the psychologist will be in developing an individually tailored plan to fit your child's needs. Based on this information and years of training and experience, a psychologist can help the child and help their family overcome challenges in implementing and modifying behavioral interventions.

In addition to those types of interventions discussed above, the psychologist can help the child and their family deal with related issues of anxiety, low self-esteem, or frequently occurring behavioral problems that often present as Oppositional Defiant Disorder or Conduct Disorder. This may involve individual therapy with the child, or a more systemic approach that involves working to help the whole family. Typical parenting practices may not work with ADHD children, especially those with co-occurring behavioral problems. As a result, parents may get frustrated, discouraged, or blame themselves for not being able to overcome the significant challenge of raising a child with ADHD. A psychologist can offer individual counseling and support for parents in addition to providing guidance and training for parenting a child with ADHD. In fact, with young children, the psychologist's primary job is working with the parents, to teach them techniques for coping with and improving their child's behavior. If parents get adequate support, they can prevent burnout and ensure that they have the energy and motivation to meet the demanding challenge of effective parenting.