ADHD: Core Features, Symptoms & Diagnostic

Criteria

James H. Johnson, Ph.D.University of Florida

ADHD: Nature of the Problem

• ADHD is a neurodevelopmental disorder of childhood that is characterized by developmentally inappropriate levels of Hyperactivity, Impulsivity, and Inattention.

ADHD: How Common is it?• It is one of the most common

disorders of childhood.• It accounts for a large number of

referrals to pediatricians, family physicians and child mental health professionals.

• Prevalence is estimated at 3 to 7 per cent of the elementary school population.

• The disorder occurs more often in males than females, with the sex ratio being about 3.4 to 1.

ADHD: Issues in Diagnosis• As noted earlier, criteria used in

the diagnosis of ADHD have variedly markedly.

• They have ranged from the very sparse & subjective Hyperkinetic Reaction of Childhood criteria seen in DSM II

• To more objective and more well delineated criteria for ADD and ADHD seen in DSM III, DSM III – R and DSM IV.

ADHD: Issues in Diagnosis• Despite the changing nature of

DSM criteria over time, the field has moved in the direction of more objective criteria, clearer decision rules, and toward criteria that are more conservative and less likely to lead to misdiagnosis of the disorder.

• These developments are highlighted in DSM IV, which is the presently accepted diagnostic system.

Focus on DSM IV in Clinical Decision Making

• As a familiarity with DSM IV diagnostic criteria is essential in clinical decision making, we will consider these criteria in some detail.

• Here we will focus separately on the diagnostic criteria for hyperactivity, impulsivity and inattention and how these characteristics are manifested by children with this disorder.

• We will then consider other criteria essential to making an ADHD diagnosis.

Clinical Presentation of Hyperactivity

• In viewing a child who is hyperactive, much of the behavior seems purposeless.

• Clinically, the child is seen as restless, fidgety, and tends to display high levels of gross body movement and/or excessive verbalizations.

• Parents often describe such children as being “squirmy”, as “not being able to sit still”, as “ talking excessively” and as “always on the go.”

Clinical Presentation of Hyperactivity

• Observation of these children at school or while working independently on tasks finds them out of their seat, moving about the classroom without permission, restlessly moving their arms and legs while working, playing with objects not related to the task and talking out of turn and making funny noises.

DSM IV Symptoms of Hyperactivity

• Often fidgets with hands or feet, squirms in seat.

• Often leaves seat in classroom or in other situations in which remaining seated is expected

• Often runs about or climbs excessively in situations in which it is inappropriate.

• Often has difficulty playing or engaging

in leisure activities quietly.

Hyperactive Symptoms• Is often "on the go" or often acts

as if "driven by a motor“.

• Often talks excessively when inappropriate to the situation

• A combined total of 6 or more of hyperactivity/impulsivity criteria are required for diagnosis.

What do we Know about Hyperactivity?

• Children with ADHD are more active, restless, and fidgety than normal children during the day and during sleep.

• There are different types of hyperactivity.– Gross Motor Activity– Restless/Squirmy

• Hyperactivity often varies according to situation.

• Degree of hyperactivity may vary with age.

Impulsivity/Disinhibition• The second group of symptoms assessed

in making a diagnosis is Impulsivity.• Here the problem is in inhibiting behavior

in the presence of situational demands• As Barkley (2006) has noted, impulsivity

is typically reflected in the “undercontrol of behavior, the inability to delay a response, to defer gratification, or to inhibit dominant or prepotent responses in specific situations.

Impulsivity: Clinical Presentation

 Impulsive children often respond quickly to situations without waiting for instructions or without actually hearing the questions being asked.

• They often fail to consider potentially negative or even dangerous consequences that may result from their behavior and often take unnecessary risks.

• They may show careless behaviors and damage other peoples property.

Impulsivity: Clinical Presentation

  These children may have problems waiting for one’s turn in a game or in lineup at school.    

• They may show problems with delay of 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.

Impulsivity: Clinical Presentation

 Situations that involve sharing, cooperation, and restraint with peers are especially problematic. 

• In interacting with peers and adults, they often interrupt others

• Frequently blurt out statements that get them into trouble because what they say may be inappropriate.

• To the layman, these children come across as immature for their age and as rude and irresponsible children with poor self control.

DSM IV Symptoms of Impulsivity

• Often blurts out answers before questions have been completed.

• Often has difficulty awaiting turn.

• Often interrupts or intrudes on others.

Six symptoms of hyperactivity and impulsivity are required for diagnosis.

Impulsivity vs Hyperactivity• While DSM IV highlights symptoms of

both impulsivity and hyperactivity it is often difficult to differentiate the two.

• Factor analyses of ratings of impulsive behaviors that are mixed in with ratings of inattention and hyperactivity have often failed to differentiate a dimension of impulsivity that can be distinguished from hyperactivity (Barkley 2006).

• Impulsive children are usually overactive and overactive children are usually impulsive.

Impulsivity vs Hyperactivity• Barkley has suggested that these

findings call into question the existence of over activity as a separate dimension of behavioral impairment apart from disinhibition.

• He goes on to suggest that – 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, Barkely has gone so far as suggesting that impulsivity/disinhibition is the primary defining feature of ADHD (Barkley 2006).

DSM IV Symptoms of Inattention

• Often fails to give close attention to details or makes careless mistakes.

• Are these careless mistakes reflective of inattention or impulsivity?

• 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

Symptoms of Inattention• Often has difficulty organizing tasks

and activities • Often avoids, dislikes, or is reluctant

to engage in tasks that require sustained mental effort.

• Might this reflect a motivational deficit rather than simply inattention?

• Often loses things necessary for tasks or activities - (Inattention or Memory???)

• Is often easily distracted by extraneous stimuli.

• Is often forgetful in daily activities • (6 or more necessary for diagnosis)

What Do We Know About ADHD Attention Problems?

• ADHD "attentional" problems may be most obvious on specific types of attentional tasks.

• Children with ADHD seem to have their greatest difficulties with sustaining their attention in responding to tasks - in being vigilant.

• Attention problems are usually seen most clearly in situations requiring the child to attend over time to dull, boring, and repetitive tasks.

Situational Variations in ADHD Symptoms

• ADHD symptoms show significant variation across situations.

• Children with ADHD do not display symptoms in all situations

• The absence of symptoms in some situations does not necessarily mean that the child does not have ADHD (e.g. Video Games, Exciting TV program).

Situations That Increase ADHD Symptoms

• When the demands of the situation are to be good, to be still, and to be quiet.

• The greater the demands the more problematic the behavior of the child will likely become.

• An exception might be in situations where the child is being continuously rewarded for complying with demands.

• In familiar situations where novelty and task stimulation are low.

Other Situations That Increase Symptoms

• Situations where there are low rates of intrinsic or external reinforcement.

• When the child is fatigued.– Studies, monitoring 24 hour activity

levels have suggested that the hours of 1 – 5 seem to be peak times for increased activity in children with ADHD.

Overview of Specific Diagnostic Criteria

• Symptom Criteria - Core Symptoms of Hyperactivity & Impulsivity and/or Inattention (Six or More Symptoms of either category).

• Duration Criterion - Symptoms have Persisted for at Least 6 Months.

• Developmental Criterion - Symptoms are Inconsistent with Developmental Level.

• Impairment Criterion - Clear Evidence of Clinically Significant Impairment in Social, Academic, or Occupational Functioning

Overview of Criteria (cont.)

  Age Criterion - Some Symptoms that Cause Impairment Present Before Age 7.

  Situation Criterion - Some Impairment from Symptoms is Present in Two or More Settings.

• NOTE. The failure to attend to full range of symptoms is not uncommon

• Presence of hyperactivity, impulsivity, and inattention is not necessarily to be equated with ADHD.

Types of ADHD• Combined Type

– Symptoms of hyperactivity, impulsivity and inattention.

• Hyperactive/Impulsive– Symptoms of hyperactivity and

impulsivity.• Predominately Inattentive

– Symptoms of inattention.

DSM IV and ADHD: A Critique

• It seems clear that the DSM IV system represents a major advance over earlier classification systems for childhood psychopathology.

• Nevertheless it seems important to consider the adequacy of this system as it relates to the diagnosis of ADHD.

• Here, Barkley (2006) has raised several criticisms regarding the usefulness of the system in diagnosing this disorder.

DSM IV & ADHD: A Critique  First, it is suggested that it is not clear

that the predominately inattentive type of ADHD is really a subtype of ADHD that shares similar attention problems with other types.

• Here, Barkley cites research suggesting– That the inattentive type seems to have

more problems with focused/selective attention and sluggish information processing

– While the combined type has more problems with persistence of effort and distractability.

Sensitivity of Diagnostic Criteria

• There are questions regarding whether diagnostic thresholds set for the two symptoms lists apply to older children and adolescents.

• This relates to the fact that hyperactive symptoms often decline with age.

• With this decline in hyperactive symptoms with age, using present cut off criteria with older children may result in reduced sensitivity for diagnosis due to failure to display enough hyperactive symptoms (although they may have been displayed earlier).

• Question – What do you do with the pt who once met criteria for combined type but no longer does due to age?

Age of Onset Criteria• Is the age of onset criterion (symptoms

before age 7) useful? • There is no empirical data to support

this particular cut off age limit (Barkely, 2006), although there are findings that those who develop the disorder early may have more severe problems.

• It has been suggested that the age of onset criterion be broadened to include symptoms beginning in childhood.

Failure to Set a Lower Limit for Diagnosis

• It has been suggested that there is a problem with the failure to set a lower age cutoff for giving a diagnosis of ADHD.

• Here, research suggests that below age 3 a separate dimension of hyperactive-impulsive behavior is often not distinguishable form aggression or defiant behavior.

• This would argue against a diagnosis of ADHD before age 3.

IQ Limit for Diagnosis?  There is a failure to indicate a lower IQ

below which a diagnosis should not be given.

• Here, it has been suggested that children with an IQ below 50 display a qualitatively different type of mental retardation than those above 50 - with genetic factors being more prominent in the lower IQ group (Barkley 2006).

• Such a cut off might be useful as decreased numbers of children with IQ’s <50 respond to stimulants.

Increased Emphasis on Hyperactivity/Impulsivity

• · Given suggestions that behavioral disinhibition is the hallmark of ADHD, Barkley suggests that a greater emphasis be placed on hyperactive/impulsive symptoms than on inattentive symptoms in describing the disorder.

• He suggests that, since these features are more useful in discriminating ADHD from other disorders, meeting a cutoff score for these items should be the first requirement in making an ADHD diagnosis.

DSM IV: Overview• This critique suggests that while

DSM IV may represent a significant advance over earlier classification systems, the system is clearly in the process of evolving.

• Further changes are likely to be found in subsequent versions of this classification system.

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