These disorders are categorized by a persistent difficulty learning keystone academic skills with an onset during the years of formal schooling. Key academic skills include reading of single words accurately and fluently, reading comprehension, written expression and spelling, arithmetic calculation, and mathematical reasoning. Difficulties learning to map letters with the sound of one’s language- to read printed words- is one of the most common manifestations of specific learning disorder. Children and adolescents with specific learning disorder experience a persistent, or restricted progress in learning for at least six months despite intervention. The learning difficulties are usually readily apparent in the early school years in most children.
Children and adolescents with Specific Learning Disorders also perform well below average for their age, and average achievement is only attained through extraordinarily high levels of effort or support. The low academic skills cause significant interference with school skills that is usually indicated by school report or teacher’s grades. These learning difficulties are considered “specific” for four reasons: (1) they are not attributable to an intellectual disability; (2) the difficulty cannot be attributed to external factors such as economic or environmental disadvantage, chronic absenteeism, or lack of education in the individual’s community context; (3) it cannot be attributed to a neurological or motor disorder and (4) the difficulty must be restricted to one academic skill or domain (i.e., reading single words, retrieving or calculating number facts).
Note that Dyslexia is an alternative term use to describe a pattern of difficulties characterized by reading and writing problems. If dyslexia is used to specify this particular pattern of difficulties, it is important to specify what and if any additional difficulties are present.