Children or adolescents may be diagnosed with a Learning Disorder when their achievement on individually administered, standardized tests in reading, mathematics, or written expression is significantly below what is expected for their age, schooling, or level of intelligence. The umbrella term "Learning Disorders" includes Reading Disorder, Disorder of Written Expression, and Mathematics Disorder.
Estimates of prevalence rates for the learning disorders vary widely, ranging between 2 and 10% of all children. Currently, more than half of all children who receive special education services have been diagnosed with some sort of learning disability. Males appear to be affected by learning disorders more frequently than females.
These days, learning disorders are thought to be neurobiological in nature, meaning they are problems that begin as a result of a brain development problem. Learning disorders are not caused by other kinds of developmental delays, speech and hearing problems, or by learning a second language as a child.
Reading disorders include problems with reading accuracy (i.e., identifying words), reading comprehension (i.e., understanding words), and reading speed. This disorder is more commonly known as "dyslexia". Despite common belief that the term "dyslexia" refers to reading or spelling words backwards, the term actually refers to any difficulty with words that is associated with a reading disorder. Reading disabilities occur in about 20% of school-aged children, and they are the most common type of learning disorder (occurring in 80% of all individuals with a learning disorder).
Reading disorders make it more difficult for children to thoroughly understand material they read. Children with reading disorders may have to read passages over and over in order to understand what they are reading. They may also stumble over or skip words or miss entire lines of text. They may exhibit problems in segmenting words and blending sounds, and difficulty associating sounds with letters.
Disorder of Written Expression
A Disorder of Written Expression (also called Dysgraphia) occurs when children have difficulties in writing, especially with handwriting, that interfere with academic achievement or with activities of daily living (e.g., writing grammatically correct sentences or paragraphs). This disorder commonly occurs in conjunction with Reading and/or Mathematics Disorder
Children with this disorder may have problems forming letters or grasping a pencil properly. They may write slowly, or complain that their writing hand is tired. They often have problems writing in cursive (script) and may prefer to print block letters instead. They may also have difficulties with spelling, grammar, punctuation, and capitalization.
A Mathematics Disorder, also called Dyscalculia, refers to difficulties and underachievement in math, either with learning mathematical concepts or in retaining mathematical information (e.g., problems with writing numbers, arithmetic, visual aspects of math, the language of math, etc.).
A child with mathematics disorder may have problems calculating the answers to math problems. They may skip problems or steps within problems. They may have difficulty in shifting between one mathematical operation and another. For instance, they may add when they should be subtracting or vice versa. They may misalign columns or rows of numbers or put decimals in the wrong place. There are many different types of Mathematics Disorders, so this is a global term that refers to all learning disabilities involving math. Disorders in this category range from mild to severe and occur in 6% to 8% of the population.