Specific Learning Disability (SLD) and ADHD

There are several definitions of specific learning disability (SLD), but most professionals define it as academic achievement falling below what one would predict given a child's measured intelligence. SLDs are defined in the federal special education law as: “a disorder in 1 or more of the basic psychological processes involved in understanding or in using language, spoken or written, which disorder may manifest itself in the imperfect ability to listen, think, speak, read, write, spell, or do mathematical calculations." [U.S.: 2015]

According to the DSM-5, 5-15% of children have a SLD. [American: 2015] Thirty-three percent of children with SLDs also have ADHD.[Margari: 2013] A notable proportion of children with ADHD also have a specific learning disability (SLD), with approximately 45% co-morbidity rates. [DuPaul: 2013]

Differentiating between ADHD and SLDs can be challenging. There are many underlying components to SLD, including deficits in language, auditory processing, memory/recall, and visual-motor/graphomotor domains. Deficits in these areas may contribute to the presentation of symptoms that are very ADHD-like. For example, a dysfluent reader may be dyslexic rather than distractible. A child who really has a memory/recall problem may look inattentive and seem to be “spacey.”The child who appears restless and slow in completing written seatwork/homework may have a bona fide processing speed problem or dysgraphia. A student with a SLD may appear off-task and not focused, but is actually struggling to comprehend all the information being presented in the classroom. Notes/assignments may not be accurately written down from the board because of visual-spatial issues rather than poor attention or distractibility. To complicate matters, children with an intellect in the gifted range may also have a learning disability. [Lovett: 2013] However, inattention due to a SLD is typically due to frustration, lack of interest, or lack of ability that manifests during academic work, unlike ADHD where inattentiveness persists in multiple domains of life. [American: 2015] SLD can present with symptoms across academic domains, especially when involving language abilities, but should not present in non-academic settings such as mealtimes.

Parents and teachers often report that effective medication treatment of ADHD results in improved reading fluency and accuracy, handwriting, on-task behavior, and overall “availability” to learn. If the child is putting in good effort and has good educational and parent support, but is still struggling academically after ADHD medications are administered, the presence of a SLD should be considered. In a study of children with hard to treat ADHD or with ADHD and co-morbid conditions, 50% were found to have an SLD. [Koolwijk: 2014] If there is a family history of SLD, then it is important to assess for the presence of a SLD when first assessing for ADHD.

Because of the complexity of these presentations, a thorough assessment is essential if SLDs are suspected. A neuropsychological evaluation is a comprehensive assessment that affords not only a differential diagnosis of SLD and ADHD, but allows careful analysis of the aforementioned domains of functioning to better understand the underpinnings of the learning problem. A battery of neuropsychological tests would typically include parent and teacher checklists and measures of I.Q., achievement, attention, memory, processing and processing speed, problem solving and reasoning, language and visual/spatial skills, fine motor skills, and emotional functioning.

The public school system is another resource for assessments when a full neuropsychological evaluation is not available. The school system can administer psychoeducational testing including I.Q. and achievement testing. The public school system has traditionally identified learning disabilities through the “Discrepancy Model.” For instance, if the child’s I.Q. score is greater than their achievement score by a certain number of points determined by a formula specific to each state, then a Learning Disability is identified. Since 2004, however, school districts are allowed to use alternative methods such as documenting ongoing underachievement as a means of determining if a student will qualify for special services due to a learning disability. For example, a number of school systems use “Response to Intervention” (RTI) to systematically monitor for a child’s response to a set of classroom interventions, and to provide additional evaluation if the classroom interventions are not sufficient to enable the child’s performance to improve.

Once an SLD has been identified, treatment consists of supporting the child's learning with evidence-based interventions that target the specific difficulties found with learning disabilities. These can include tutoring, resource classes, and/or special education, and medications for ADHD if present. Children who have been accurately assessed and diagnosed have a greater chance of making good academic progress. Early intervention for SLD is critical for outcomes. They may also have a greater sense of efficacy and self-esteem because they better understand their own learning style and are empowered by the educational interventions. [Barkley: 2014]