ATTENTION DEFICIT HYPERACTIVITY DISORDER:
Core Features and Diagnostic Issues
CORE FEATURES
While views regarding the core symptoms of ADHD often change over time, at present the primary features of the disorder are thought to be chronic and developmentally inappropriate problems of inattention, impulsivity and hyperactivity.
While the nature of these core symptoms would, at first seem to be quite obvious, it would seem useful to consider them in a bit more detail.
PROBLEMS OF INATTENTION
What is Inattention? What is an Attention Deficit?
Attention is a multidimensional construct.
IT CAN REFER TO
· How alert the child is and how quickly he/she can orient to new stimuli
· How selective the child is in what he/she attends to
· How easily he/she is distracted
· How long he/she can sustain attention
Inattention can refer to a number of things!
Also, sometimes what looks like inattention can actually be the result of other factors (e.g., impulsivity, failure to remember, lack of motivation, oppositionality) - need to keep this in mind in thinking about certain of the DSM criteria.
This variability in the nature of attention and the possible confounding of attention with other constructs can be seen from inspection of the DSM IV inattention criteria (Need 6 or more to be considered inattentive).
· Often fails to give close attention to details or makes careless mistakes in schoolwork, work, or other activities. (Q - Are careless mistakes reflective of inattention or impulsivity? Might this item tap either construct?)
· Often has difficulties sustaining attention in tasks or play activities.
· Often does not seem to listen when spoken to directly.
· Often does not follow through on instructions and fails to finish homework, chores, or duties in the workplace, Not due to oppositional behavior or failure to understand instructions (Is this due to attention problem or motivational deficit?)
· Often has difficulty organizing tasks and activities (Are inattention and organizational skills the same thing or does this criteria simply reflect a problem which may sometimes result from inattention but may result from other factors as well?)
· Often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort such as schoolwork or homework (is this reflective of inattention or a motivational deficit?)
· Often loses things necessary for tasks or activities such as school assignments, pencils, books or tools (Inattention or memory?).
· Is often easily distracted by extraneous stimuli.
· Is often forgetful in daily activities (Inattention or memory?).
Question
To what extent do the DSM IV criteria reflect attentional difficulties and to what extent are they confounded with impulsivity, memory, motivational deficits or other factors?)
Despite some lack of preciseness in the criteria, research to date has provided us with some information about attention problems in children with ADHD. While children with this disorder do have "attentional" problems, they seem to have attentional problems of certain types and do not necessarily display them in all situations.
· Children with ADHD have their greatest difficulties with persistence of effort or sustaining their attention in responding to tasks - in being vigilant.
· While one can sometimes see inattentiveness in free play situations, attention problems are usually not the most obvious here.
· Attention problems are usually seen most clearly in situations requiring the child to sustain attention in dull, boring, and repetitive tasks such as independent schoolwork, homework, or in doing chores.
· Some research suggests that the problem displayed by children with ADHD is less one of distractibility and more one of diminished persistence or effort sustained to tasks that have minimal intrinsic appeal or minimal immediate positive consequences for completion.
· While ADHD children are not necessarily more distractible than normal children they my appear distractible due to their difficulty in inhibiting response to stimuli having intrinsic reward value when responding to other tasks which are less rewarding.
THE PROBLEM OF IMPUSLIVENESS
The second core feature of ADHD, as it presently conceptualized is impulsiveness, or the deficit in inhibiting behavior in the presence of situational demand.
As Barkley (1998) has suggested ---
Impulsive behaviors most often seen in children with ADHD are reflected in the under control of behavior, the inability to delay a response or deter gratification, or inhibit dominant or prepotent responses in specific situations.
Clinically children with ADHD are found to :
· Respond quickly to situations without waiting for instructions or without hearing the question being asked.
· They often fail to consider potentially negative or even dangerous consequences that may result form their behaviors and often take unnecessary risks.
· They may show careless behaviors and damage other peoples property.
· They may have problems waiting for one's turn in a game or lineup at school.
· They may show problems delaying gratification.
· They often take shortcuts in tasks - finding a way to apply the least amount of effort and in taking the least amount of time in dealing with tasks they find boring or aversive.
· Situations that involve sharing, cooperation, and restraint with peers are particularly problematic.
· In interacting with peers and adults they often interrupt others and frequently blurt out statements that get them into trouble because what they say may not be appropriate..
SUCH CHILDREN MAY COME ACROSS AS IMMATURE FOR THEIR AGE AND AS RATHER RUDE AND IRRESPONSIBLE CHILDREN WITH POOR SELF CONTROL.
DSM IV Impulsiveness criteria is indexed by only three items.
· Often blurts out answers before questions have been completed.
· Often has difficulty awaiting turn.
· Often interrupts or intrudes on others (e.g., butts into conversations or games).
As with inattention, it is sometimes difficult to know whether behaviors reflected in these criteria relate specifically to impulsivity/disinhibition or to other factors.
For example, the problems with the child who interrupt and intrudes on others by butting into conversation or games might be related to disinhibition
or
the problem might relate more to the fact that the child has difficulties attending to an interpreting social cues.
There is the larger issue in differentiating between what is impulsive responding and what is hyperactivity.
Studies have that have factor analyzed ratings of impulsive behavior that are mixed in with ratings of inattention and over activity have often failed to differentiate a dimension of impulsivity that is distinguishable from hyperactivity.
Impulsive children are overactive and overactive children are impulsive.
Such findings have led Barkley (1998) to suggest that:
These findings call into serious question the existence of over activity as a separate dimensions of behavioral impairment apart from poor inhibition in these children..
He goes on to suggest:
It also strongly implies that the more global problem of behavioral disinhibition unites the two symptoms.
Indeed, in considering the importance of this core symptom of impulsivity, Barkley (1998) has gone so far as suggesting that impulsivity/disinhibition is the primary defining feature of this disorder..
QUOTE "Evidence that behavioral disinhibition or poor regulation and inhibition of behavior is in fact the hallmark of this disorder is so substantial that it can be considered (BARKLEY, 1998, P. 6).
Several lines of evidence support this position:.
· First, Research suggests that it is not inattention that distinguishes ADHD children from other clinical disorders or from normal children as much as it is hyperactive/impulsive and disinhibited behavior.
· Second, when objective measures of the three classes of ADHD symptoms are subjected to discriminant function analysis, it is the symptoms of impulsive errors, typically on vigilance tasks or those assessing response inhibition and excessive activity that best discriminate and classify ADHD children.
· Third, in field trials where DSM III-R criteria were studied to determine those which most reliability differentiated children with ADHD from children with other disorders and from normals it was primarily symptoms suggestive of impulsivity, disinhibition, and poorly regulated behavior that differentiated the groups,
For reasons such as these, attentional problems are seen as possibly secondary to a disorder of behavioral regulation and inhibition, rather than as a primary and distinct deficit.
SYMPTOMS OF HYPERACTIVITY
The third characteristic of children with ADHD is their excessive and developmentally inappropriate level of activity.
Clinically, the child is seen as restless, fidgety, and tends to display high levels of gross body movement and/or excessive verbalizations.
Much of the behavior seems purposeless.
Parents describe the child as being squirmy, as not being able to sit still, as talking excessively, and as always on the go.
Observations of these children at school finds them out of their seats, moving about the room without permission, moving their arms and legs while working, playing with objects not related to the task, and talking out of turn and making funny noises.
SPECIFIC DSM IV CRITERIA FOR HYPEARACTIVITY:
· Often fidgets with hands or feet, squirms in seat..
· Often leaves seat in classroom or in other situations in which remaining seated is expected (is this hyperactivity or impulsiveness?).
· Often runs about or climbs excessively in situations in which it is inappropriate (Is this hyperactivity or impulsiveness?)
· Often has difficulty playing or engaging in leisure activities quietly.
· Is often "on the go" or often acts as if "driven by a motor"
· Often talks excessively when inappropriate to the situation (is this hyperactivity or impulsivity?).
A combined total of 6 or more of these criteria and the preceding impulsivity criteria are required for diagnosis.
Existing research clearly suggests that:
· Children with ADHD are more active, restless, and fidgety that normal children during the day and during sleep.
· Just like there are different types of inattention there are different types of hyperactivity.
· Measures of ankle movement and locomotion seem to most reliably distinguish between ADHD children and normals.
· Some studies have also found wrist movement and total body movement to differentiate ADHD cases from normals..
· Studies of activity levels have often shown that the degree of hyperactivity often varies according to situation, suggesting that it may be the failure to regulate activity level to setting that is especially problematic.
While we have alluded to the basic diagnostic criteria that are associated with ADHD in the DSM IV system, it would seem important to consider the issue of DIS IV diagnosis in more detail.
DSM IV DIAGNOSIS OF ADHD
Compared to prior classification systems for the diagnosis of ADHD, DSM IV can be rated positively on a number of counts.
· Criteria were derived by a committee made up of leading experts in the field..
· The criteria were designed to be consistent with the research literature pertaining to this disorder.
· Final criteria were based on the results of extensive field trials which assessed the usefulness and adequacy of these criteria with some 380 children from 10 sites in North America..
· Items making up diagnostic criteria were selected primarily from factor analyses of items derived from parent and teacher rating scales which had already been shown to be highly intercorrelated with one another and to have validity in distinguishing ADHD children from other groups.
· The separation of criteria into separate groupings reflecting symptoms of inattention and hyperactivity/impulsivity was also based on factor analytic findings which supported these groupings.
· Cutoff points for the number of symptoms necessary for diagnosis were determined by an examination of different cut off scores in field trials, providing some empirical basis for these cut off points and the grouping of criteria into clusters (Inattention, Hyperactive/Impulsive.).
· Pervasiveness of symptoms was included as a criteria for diagnosis. This requirement is new to DSM IV and consistent with European views of this disorder, which highlight pervasiveness of symptoms as essential for diagnosis) - There is a potential problem with this, as the failure to find pervasiveness of symptoms may relate to reporter bias in some situations rather than the absence of symptoms. A partial solution might be to demand a history of impairment across situations rather than present day reports of pervasiveness across situations. Related to this issue, it is noteworthy that agreement on the presence of symptoms by parent, teacher, AND clinician restricts the diagnosis of ADHD to approximately 1% or less of the child population.
· There was a return to sub-typing ADHD, with and without hyperactivity, as was the case with DSM III. Here one can again provide a diagnosis for children and adolescents who show only symptoms of inattention (ADHD, Predominately Inattentive Type), those who show symptoms of hyperactivity and impulsivity (ADHD, Predominately Hyperactive-Impulsive Type, and those who show all three types of symptoms (ADHD, Combined Type.
· Impairment was added as a requirement for diagnosis. This addition relates to the fact that the presence of symptoms does not necessarily warrant a diagnosis. This impairment criterion important in differentiating children with ADHD from those who simply have problems with inattention, impulsivity, and activity level but who do not show evidence of impaired functioning.
In general, these diagnostic criteria, while not judged to be perfect by most, still represent the most adequate system for diagnosis of ADHD yet developed.
Despite these positive attributes, Barkley (1998) has highlighted a range of issues that need to be considered with regard to this system and its adequacy. Here he notes:
· It is not clear that the inattentive type of ADHD is actually a subtype of ADHD, which shares a common attention deficit with other types. In addition to other research findings, Barkley cites studies which suggest that the inattentive type seems to be characterized more by problems in focused selective attention and sluggish information processing while the combined type is characterized more by problems of persistence of effort and distractibility. It is also the case that problems of inattention can result from anxiety, depression, and the effect of post-traumatic stress disorder.
· It is unclear whether the Hyperactive-Impulsive type is really distinct from the Combined type as most H-I types are preschoolers who become Combined types as they become school-age children and develop attentional problems.