Fiedorowicz, C., Craig, M. J., Phillips, M., Price, A., &
Bullivant, M. G. (2015). Learning Disabilities Association of Canada Position Paper:
TO REVISE OR NOT TO REVISE -
The Official LDAC Definition of Learning Disabilities Versus DSM-5 Criteria MARCH 2015
This position paper written by the Learning
Disabilities Association of Canada (LDAC) discusses whether to revise or not to
revise its learning disability definition in light of DSM5.
The bottom line is that the Canadian association
decided not to revise its definition and not to adopt the DSM5 definition.
Out of this important document, I'll
focus on the LDAC's criticism of the DSM5 definition in two aspects: the IQ
score's role in learning disability (LD) definition, and the necessity of
identifying processes or cognitive abilities that lie at the base of the child's
difficulties in reading, writing or arithmetic.
First,
a reminder of the DSM5 positions in these two issues:
As for
the role of the IQ score in LD definition, DSM5 says:
"Specific learning disorder affects learning in individuals who
otherwise demonstrate normal levels of intellectual functioning (generally
estimated by an IQ score of greater than about 70 plus or minus 5 points…)"
I object to this sentence on the following
grounds:
It’s unclear how an IQ score of 65 can be
considered as “a normal level of intellectual functioning”, especially in light of the fact that a
standard score of 85 (1 standard deviation below average) in an achievement
test is considered by the DSM5 to be substantially below average and meets the
first criterion for LD diagnosis (low achievement).
It's hard to imagine how the low
achievement of a child who has an IQ score of 65 can be seen as “unexpected
underachievement”. DSM5 sees unexpected underachievement as one of the
hallmarks of LD: “The phrase “unexpected academic underachievement” is often
cited as the defining characteristic of specific learning disorder in that the
specific learning disabilities are not part of a more genera learning
difficulty as manifested in intellectual disability or global developmental
delay.”
As
for the necessity of identifying processes or cognitive abilities that lie at
the base of the child's difficulties in reading, writing or arithmetic: DSM5 does not require the identification
of a neurobiological/cognitive cause for low achievement. DSM5 learning disorder definition (like all DSM5
definitions) refers to the symptoms and to exclusionary factors/differential
definition and not to factors that cause the symptoms. The DSM5 learning disorder experts claim that
the relationship between deficits in psychological/cognitive processes and
reading is probabilistic and not deterministic.
This means that it’s not possible to use a specific cognitive profile to
establish or to reject a reading disability diagnosis. The experts argue that it’s unclear what the
psychological processes related to math or written expression are.
Now for
the Learning Disability Association of Canada's positions on these issues. The
positions are copied verbatim [with my additions in brackets].
As for
the role of the IQ score in LD definition:
"The LDAC Definition of Learning
Disabilities has clearly stipulated that an individual with learning
disabilities has at least average to above average intelligence. This typically
has been determined by formal psychological assessments performed by qualified
professionals. Learning disabilities have been differentiated from intellectual
impairment which was diagnosed when an individual assessed by a qualified
professional has a measured IQ at 70 or below on a standardized intellectual
test. The distinction between learning disabilities and an intellectual
impairment has been considered a key issue as it can provide insights about
potential for learning and types of interventions appropriate for each group.
Individuals with intellectual impairment are not expected to manage the
rigorous interventions appropriate for individuals with learning disabilities
at the same level and rate of learning. Differential, targeted interventions
and accommodations increase the likelihood of success for each group."
"One challenge
posed by the DSM-5 is that 70 +/- 5 is described as a “normal” level of
intellectual functioning. There
is disagreement about this interpretation and much discussion about what should
be considered “average” intellectual functioning. This creates a “gray
area” for psychologists and requires flexibility when diagnosing a learning
disability. The IQ scores need to be interpreted cautiously in the context of
all of the other information gathered about the individual. Processing
difficulties experienced by individuals with learning disabilities may have a
negative impact on their performance on a test of intelligence. A flexible
approach is necessary."
[As I understand it, LDAC does not
consider 70 +/- 5 to be normal intellectual functioning, but also recommends
taking into consideration the effects of the cognitive difficulties of the LD
person on his full scale IQ score. We are
to see the IQ score in context.]
As for
the necessity of identifying processes or cognitive abilities that lie at the base
of the child's difficulties in reading, writing or arithmetic:
"… the negative impact of not including
an evaluation of intellectual abilities and cognitive processing [in LD
diagnosis] needs to be given careful consideration. The unique contribution of
psychology to the essential multidisciplinary approach to learning disabilities
is the knowledge/skill-set required for assessment, diagnosis and follow-up… Both intellectual assessment and data concerning
a range of psychological processes provide a more comprehensive profile of
strengths and weaknesses of the individual with learning disabilities and are
critical elements of a comprehensive plan for individually targeted
intervention and accommodation... the new [DSM5] criteria could increase the
risk of false positives and over-diagnosis by including individuals who have
academic challenges for reasons other than learning disabilities."
"With… an analysis of underlying psychological
processes, it is possible to examine the roots of the difficulties, rather than
simply restate and validate their existence. The impact of the learning
disability throughout an individual’s lifespan can then be better understood."
"Cognitive processes go beyond what
is measured in standardized IQ tests, although the clusters of abilities assessed by IQ tests can
provide valuable information about cognitive abilities and suggest areas of
difficulty that warrant further exploration. Academic learning difficulties are
logically related to observed deficits in cognitive processes. Examples
of cognitive processes under consideration include phonological processing,
language processing, attention and memory (working memory, long-term memory and
short-term memory), processing speed, visual perception, visual-motor
processing, and executive functions."
" …A
comprehensive assessment goes beyond tests and important information can be
obtained from observations of the quality of performance, test-teach-test opportunities,
interviews, and history. This information, together with a growing
body of evidence linking cognitive processing deficits to academic achievement,
is important for describing an individual learner’s profile of strengths and
needs. It is this profile that is critical for designing intervention for a
student with learning disabilities."
"Harrison &
Holmes (2012) recommend a three component model for LD assessment and diagnosis
... which they say is reflected in the LDAC…
definition...The … model includes: below average academic achievement relative
to most other individuals; impairments in the cognitive processes responsible
for normal development of the deficient academic abilities; and ruling out
other reasonable causes for the academic deficits, including academic
difficulties due to generally lower abilities required for reasoning and
learning." [This model is in line with the Flanagan definition of LD in
light of CHC theory].
To summarize, the Canadians
write:
"With respect to the intelligence
testing issue, there is no direct statement in the DSM-5 to negate the
continued use of intelligence testing. Rather, it is no longer necessary
[according to DSM5] unless there is suspicion of intellectual impairment… If
both an intellectual profile and a cognitive processing profile are no longer
included in the evaluation to determine diagnosis of learning disabilities,
critical information is lacking in understanding the strengths and weaknesses as
well as determining interventions and accommodations that best meet the needs
of the individual. Ultimately, the goal is to help individuals with learning
disabilities maximize their opportunities for success…. Therefore, an
assessment to identify and diagnose Learning Disabilities that includes some or
all of the following provides a broader perspective: intellectual and cognitive
processing abilities, executive functions, neuropsychological profile, learning
styles and strategies, and social-emotional status in addition to academic
basic skills. With more information about the individual, it is anticipated
that interventions including teaching and learning strategies as well as
accommodations can be recommended to best meet the needs of each individual
learner."
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