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Rethinking Learning Disorders

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American



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For most people, learning to read, write, add, or subtract seems straightforward and elementary. But as both a professor of special education and a scientist who studies learning in children with neurodevelopmental issues, I know that, acquiring these essential academic skills is indeed a complicated and effortful endeavor for some and that the problems they and their families experience are often just as complicated. The psychiatric community has been rethinking learning disorders in an effort to benefit these young people. How does someone's ability to read fluently affect that individual's ability to understand mathematical reasoning? What are the best measures for determining a person's ability to learn? Is the process more about IQ, specific cognitive abilities, achievement, or teaching? Or all of these factors? These are the questions that I and a group of experts investigated as we sought to update the diagnostic criteria for learning disorders. The result of our work, reflecting the input of international experts, educators, and advocacy groups, will be published in May in the new edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). DSM contains descriptions, symptoms, and other criteria for identifying these conditions, providing a common language for clinicians to communicate about their patients. In an effort to capture the wealth of knowledge gained since the manual was last published nearly 20 years ago, we made two significant changes. First, we revised the category into a single, overarching diagnosis--called specific learning disorder--that incorporates deficits impacting academic achievement. Past criteria limited learning disorders to three specific diagnoses: namely, disorders of reading, mathematics, and written expression. But research has shown that these areas of learning are highly interrelated and shouldn't be divided as though they were separate disorders. Consider, for instance, a 7-year-old named Emily, who begins falling behind her classmates in recognizing and sounding out words. Under the previous criteria, she likely would be diagnosed with a reading learning disorder without any consideration of how she is doing in other areas like spelling and math. Yet we know that specific symptoms, such as difficulty in reading, are just symptoms. And in many cases, one symptom points to a larger set of problems. These problems can have long-term impact on a person's ability to function because so many activities of daily living require a mastery of number facts, written words, and written expression. That's why the DSM-5 criteria now describe shortcomings in general academic skills and provide detailed specifiers for the areas of reading, mathematics, and written expression. With Emily, the new diagnosis allows a clinician to identify any other learning difficulties with those specifiers. For example, the clinician can note that Emily has word reading difficulties (or can use the term dyslexia, if preferred by the clinician or family), as well as problems with math. The specifiers also can help to capture developmental changes in how learning disorders manifest as academic demands increase by grade. By middle school, for instance, Emily may be reading words accurately, albeit slowly, but having trouble understanding what she has just read. Our second major change was removing the requirement for a pronounced gap between a person's IQ and academic achievement scores. When I met Josh, he was 19 and struggling with his college classes. This wasn't the first time he'd faltered in school. When he was 10, a clinical psychologist confirmed his reading problems. Even though it was clear that Josh needed extra help in order to succeed academically, he didn't meet the criteria for a learning disorder because the discrepancy between his IQ and achievement scores was not big enough. This meant he wasn't eligible for special education services. Such earlier intervention might have helped him avoid the issues he was experiencing nearly a decade later in college. Research has confirmed many problems with the IQ discrepancy requirement, including over-identifying learning disorders in individuals with high IQ scores and under-identifying people with lower-range scores. For example, what if a student has an especially high IQ but average achievement? While the discrepancy is there, it does not necessarily mean a student has a learning disorder; other issues, either mental or medical, could be at play. By contrast, a student with a very high IQ whose average achievement takes extraordinary effort and support may indeed have a learning disorder. And what about the young elementary school student who has a low-average IQ and struggles to match letters with their sounds and, in turn, to read words? The child may also have a specific learning disorder despite the small discrepancy between IQ and achievement. Importantly, the research shows that this student will likely benefit from the same type of reading intervention program as will a student with a large discrepancy between IQ and achievement. Eliminating the IQ discrepancy forced my colleagues and me to answer a tough question: What standard of measurement should replace it? Like many of my colleagues and parents involved with various learning disability associations, I assumed that deficits in specific cognitive abilities underlying the learning difficulties might serve as a replacement. However, the research did not support the inclusion of specific cognitive impairments in the diagnostic criteria because relationships between such deficits and learning difficulties were not robust. Thus, we proposed that the new criteria include a low-achievement indicator and require that academic problems must have persisted for at least six months despite intervention efforts. The compromise reached provides clinicians enough guidance to diagnose with specificity and accuracy, but it doesn't compel them to include or exclude individuals based on specific scores or grades. Early identification and intervention are particularly important for learning disorders. When children like Emily and Josh get a diagnosis that truly reflects their learning difficulties, they are able to access services and treatment options that will help to ensure their academic progress year after year. At the end of the day, that should be what we all want. Click here to see a video of DSM-5's Neurodevelopmental Disorders Work Group Chair Dr. Susan Swedo discussing the impact of these changes. Image: iStock photo.

Rosemary Tannock, PhD, holds a Canada Research Chair in Special Education and Adaptive Technology at the Ontario Institute for Studies in Education in the University of Toronto. She is a Senior Scientist at the Hospital for Sick Children in Toronto, a Professor of Psychiatry, and Professor of Special Education & Adaptive Instruction at the University of Toronto. She has research appointments with the Graduate Departments of Education and Psychology at the University of Western Australia. Her clinical research program investigates the causes and treatment of attention-deficit/hyperactivity disorder (ADHD), with a specific focus on its cognitive manifestations and overlap with learning disabilities. She and her colleagues recently developed TeachADHD, a set of integrated multimedia resources on ADHD for teachers. She has received the Citizen of the Year Award for mentorship from the Research Institute of The Hospital for Sick Children, Visiting Scholar and Distinguished Visitor Awards from the University of Western Australia a Distinguished Achievement Award from the Association of Educational Publishers, and is on the Steering Committee for the World Health Organization International Classification of Functioning, Disability and Health (ICF) – Development of Core ICF Sets for ADHD.

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