Attention Deficit Disorder, and thus many parents and teachers
believe that the primary problem is distractibility or poor
attention, in reality this disorder is primarily a disorder of
impaired executive function. When an individual has ADHD, executive
functions are not emerging or unfolding as expected for the child
chronological age. By executive functions I refer to a wide range of
central control process of the brain that temporaneously connect,
prioritize and integrate cognitive functions in the same manner that
a conductor directs a band. Clearly, this does not refer to a
single task at a given point in time such as focusing on getting a
hamburger when hungry, or pushing a button at a given moment in
order to stop a character is a video game from going forward. But,
it does mean there is impairment in the ability to sustain
concentrated focus on a task that requires constant monitoring and
adjustment, as well as intermediate and long-term projection into
the future such as driving a car, following a complicate classroom
lecture or interacting with others and anticipating their reactions
and the long-term outcomes of my statements or actions. In short,
impaired executive functions negatively impact the real stuff of day
to day life.
structures that support these executive functions are not fully
developed at birth. The neural networks underlying intentional
control begin to develop between the ages of two and four, but
continue to develop into the twenties. Between the ages of six and
fifteen, we see significant growth of the collosal isthus that
supports associative relay, simultaneously there is a substantial
amount of pruning of synaptic connections which are not routinely
engaged. Dopamine, norephinephrine and serotonin transmitter
systems, likewise continue to develop into young
adulthood. Significantly, after puberty during adolescence brain
myelination increases 100%.
We also know from
MRI studies of normal children that cortex thickness peaks at 11
years of age for females and 12.5 years of age for
males. Thereafter, gradual pruning occurs progressing caudally to
rostrally to insure more efficient circuits.
functions physiological capacity develops throughout childhood into
adolescence and young adulthood, it is clearly not fully developed t
in early childhood and we cannot expect the same level of executive
control from children as we would from adults. Still, when compared
to non disabled peers, executive function impairments are often
noticeable by age seven or eight, though in some cases they might
not be recognized until significantly later.
In early childhood,
parents and other caregivers perform all the executive functions for
children. Support or scaffolding of executive functions is provide
by adults who show, direct, help, remind, coach and critique
children. For the normal child, this scaffolding is gradually faded
out as the child becomes capable of performing these functions for
themselves. In adolescence and adulthood scaffolding may be provide
by friends, teacher, coaches, spouses and supervisiors when
executive functions have not developed as anticipated, but for this
to be arranged, everyone needs to be aware of the diagnosis,
understand its practical implications and make a commitment to
provide appropriate supports.
In fact, impaired
executive function might not be observed in young children if they
live in a home which is well structured and attend a school setting
that is likewise well structured. When ample predictability and
scaffolding support is present, it may be that no one recognizes the
child’s deficits until middle school when executive challenges begin
to increase. In other cases, they are obvious in preschool years.
So, why are
executive functions important?
functions are needed to prioritize, start, sustain, shift, stop,
inhibit and integrate various cognitive functions. They permit one
to manage one’s own behavior and depend upon the ability to utilize
memory of previous experience without continual moment by moment
guidance from others.
We cannot rate
specific tasks for level of executive function demand because each
task will have a different executive function load for each
individual. This is because tasks which are unfamiliar to the
individual require more executive function capacity; while well
practiced tasks require less executive function capacity. Most
executive functions actual operate unconsciously. So, if a child
has gone camping week after week for the past year, and habitually
packed the same emergency equipment, being asked to pack for a
camping trip on his own will not require the same level of executive
function as it would of another child who had never been camping
before and needed to consider each item to be packed rather than
simply recall it.
stress has a curvilinear effect on executive functions. Too little
stress is not sufficiently challenging to invoke executive functions
and too much overwhelms the system. This is why the complexity of a
task much be tailored to the child’s current capacity and not based
on the general education curriculum. It is also why parents walk a
very fine line between setting expectations that are too low, and
being perceived as nagging a child to do something they aren’t
equipped to do. The field of play where each child can function at
his best is different for each child, so one parent cannot not apply
another parent’s rule of thumb.
does executive functioning encompass?
Russell Barkley has
presented a model of executive function impairment that is present
in the hyperactive and combined types. From his perspective,
inhibition is the central explanatory concepts of ADHD, but there is
convincing evidence to support both excitatory (activating) and
inhibitory problems in ADHD.
presents a more complex model of impaired executive functions in
ADHD. He sees it as dimensional, that is, we are not looking at an
“all-or-nothing” situation. The fact is that everyone sometimes
evidences impairments in these functions. The key in the case of
ADHD is that the impairment is both severe and chronic; and even
when they are interested in an activity or during an apparently good
period, individuals with ADHD may continue to evidence impairments
in executive functions.
Activiation or Excitation. Here we observe problems
organizing tasks and materials, as well as difficulty estimating
time and task durations as well as difficulty prioritizing tasks.
There is also difficulty initiating work on new tasks. These are
problems that any parent of an ADHD child can attest to, and they
may have a substantially disruptive effect upon family functioning.
Shift and Sustained Attention. Individuals with ADHD
evidence a tendency to lose focus when trying to listen or to plan.
They are easily distracted by both internal and external stimuli.
Consequently, the frequently forget what they have heard and need it
to be repeated or forget what they have read and need to re-read it.
Impaired ability to regulate Alertness, Effort and Processing Speed.
Individuals evidence problems regulating sleep and alertness. They
may have difficulty both falling asleep or waking up fully.
Moreover, they quickly lose interest in tasks; particularly when
those tasks are lengthy and show a consistent pattern of not
sustaining effort over time.
Management of Frustration and Emotional Modulation. Though
not included in the DWM-IV diagnostic criteria, professionals
experienced in working the individuals with ADHD find that the
emotional impact of their emotions upon their thoughts and actions
is excessive. They exhibit frustration, irritation, feelings of
hurt, worry and desires that spread throughout their mind and
persist. In short, they are not able to set these things aside and
more onto other more productive thoughts. Often they appear more
sensitive to these feelings than others and to experience them over
what appears to others to be relatively minor events.
Working Memory. Individuals with this disorder have
difficulty remembering to remember; even though others give them
frequent reminders and cues. They simply have difficulty holding one
or more things in their mind at the same time while attending to
other tasks. So, if they are searching for the QL slot to file a
file, they are not able to simultaneously keep in mind that P
precedes Q and is towards the end of the alphabet, so they begin
looking under A or keep repeating the alphabet over and over to
themselves until they find the correct spot. They seem to have an
inadequate “search engine” for activating stored memories when they
need them to integrate with current information in order to guide
their present thoughts and actions.
Monitoring and Regulation Even when individuals with ADHD
are not hyperactive or impulsive they have difficulty controlling
their actions. It is hard for them to slow down or speed up as
appropriate for different tasks. Living with these children is
like driving a car with a broken gas pedal that goes at 50-70 miles
per hour whether you are in a school zone or on the highway. These
individuals do not evaluate ongoing situations carefully, and as a
result respond inappropriately. It is difficult for them to monitor
and modify their own actions in order to align them with the current
situation or their own goals.
What caused my
child to have ADHD?
The question that
parents like answered is how their child came to have impaired
executive functions. Some times as in the case of ADHD it is an
inherited developmental disorder At other times, executive
functions can be impaired by a mild traumatic brain injury perhaps
sustained in a car accident or by diseases such as Alzheimer’s. The
difference between developmental impaired executive dysfunction and
acquire dysfunction is that in the case of the developmental
impaired adequate executive function capacity was never present. In
the case of acquired dysfunction the individual’s brain development
normally and then some insult cause executive functions to be
At one time, ADHD
was assessed solely on the basis of overt behavior because it was
believed to be a disruptive behavior disorder of childhood. Now we
realize that the executive function impairments of ADHD are
primarily cognitive and covert. There are two current models for
assessing these executive impairments: neuropsychological evaluation
and clinical interviews of past and present self-management. In
fact, neuropsychological assessment includes both tests such as the
WCST, Stroop, Rey-Osterreich , Tower of Hanoi and clinical
interviews and thus gives a more comprehensive picture and more
Single tests in
isolation, however, are insufficient because most tests attempt to
isolate, quantify and measure effects of a single variable presumed
to tax a single functional process butexecutive functions involve
simultaneous management of a range of different functions. Thus,
the evaluator must look at the global view. In short, ADHD is a
developmental impairment of the self-management system of the brain
wherein self-management of and by emotion is impaired. While it may
be noticeable in childhood, it may not be diagnoses until the
individual experiences challenges during adolescence or young
adulthood. Although many observers believe that the individual with
ADHD is exercising an insufficient amount of willpower, the fact is
that there is a chemical imbalance in the brain that is manifest in
terms of imbalance brainwave patterns. True the causes of ADHD are
primarily genetic, but environmental supports and stressors modify
the expression of the disorder. In short, the more supports and the
less stressors, the better the individual’s overall level of
functioning is likely to be.
More to follow in
Presented as a
Community Service by,
Susan Crum, B.S.,
Special Needs Coach
Brown, T. E. (2000).
Attention-Deficit Disorders and Comorbidities in Children,
Adolescents, and Adults. Washington, DC: American Psychiatric
Gilbert, D. e. (2006). Comparison of the
Inhibitory and Excitatory Effects of ADHD Medication Methylphemidate
and Atomoxetine on Motor Cortex. Neuropsychopharmaco