Terms such as learning disorder and learning disability often are used interchangeably. The International Statistical Classification of Diseases and Related Health Problems–10th Revision (ICD-10) uses the term Specific Developmental Disorders of Scholastic Skills in referring to this category of Disorders of Psychological Development. It is further subdivided into disorders having to do with specific scholastic skills such as reading, spelling, math, and so forth. There will be reference to ICD-10 definitions and diagnostic criteria at various points in the discussion of learning disorders in this chapter. However, the coverage of the topic will be broader than that and will incorporate conceptual, empirical, and historical perspectives as well.
A major stride in the definition of learning disabilities came in 1981 from the National Joint Committee on Learning Disabilities (NJCLD). The NJCLD defined learning disability as "a generic term that refers to a heterogeneous group of disorders manifested by significant difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning, or mathematical abilities. These disorders are intrinsic to the individual and presumed to be due to central nervous system dysfunction. Even though a learning disability may occur concomitantly with other handicapping conditions (e.g., sensory impairment, mental retardation, social and emotional disturbance) or environmental influences (e.g., cultural differences, insufficient/inappropriate instruction, psychogenic factors), it is not the direct result of those conditions or influences" (Hammill et al, 1981).
This definition went further than the earlier one contained in the Education for All Handicapped Children Act of 1975 (P.L. 94–142) by stipulating specifically that a learning disability must be presumed to be due to central nervous system dysfunction. Although this was implied in previous definitions, never before had it been made explicit. Accordingly, the later definition helped to resolve a good deal of confusion and ambiguity involving identification and differential diagnosis. Deficiencies in academic achievement can arise from a variety of factors, operating alone or in combination. To say that there is a learning disability, however, means that there must be a basis for inferring that some form of brain dysfunction is involved.
ESSENTIALS OF DIAGNOSIS ICD-10 Diagnostic Criteria for Disorders of Scholastic Skills
The International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10) identifies three types of Specific Developmental Disorders of Scholastic Skills including: Specific Reading Disorder (F81.0), Specific Spelling Disorder (F81.1), and Specific Disorder of Arithmetical Skills (F81.2). The category is further broken down to include: Mixed Disorder of Scholastic Skills (F81.3), Other Developmental Disorders of Scholastic Skills (F81.8), and Developmental Disorder of Scholastic Skills, Unspecified (F81.9).
In each disorder, the diagnosis depends on documentation that:
There is a disturbance in the normal patterns of skill acquisition evident from early stages of development, and which are not due to any form of acquired brain trauma or disease
There is significant impairment in the affected skill(s) that is not simply due to low mental age, lack of opportunity, inadequate schooling, ...