Developmental Disorders

Definition of Developmental Disorders

The implications of developmental disorder classification and resultant diagnostic labels have a major impact on diagnostic systems, scientific study of developmental disorders, and service-based educational intervention and treatment programs for children and youth. The largest impact on children and youth is related to how such definitions become incorporated into administrative rules for the delivery of special education services in schools and related supports in community-based rehabilitation and treatment settings.

Early definitions of developmental disability are relevant to the understanding of the current status of developmental disorders. The earliest definitions of developmental disabilities were crafted in Public Law 91–517 in 1970. This law was an outgrowth of the work of several forward-thinking individuals who assisted on the president's panel on mental retardation at the request of President John F Kennedy in 1961. This effort was directed toward prevention in mental retardation worldwide. This panel and its outcomes set the stage for subsequent legislation related to developmental disabilities and later, developmental disorders. This presidential panel made important contributions that expanded early definitions and approaches to the treatment of developmental disabilities. These contributions included keeping children with disabilities in their [Page 157]normal or local environments; supporting those with physical impairments; encouraging a blended continuum of medical, educational, and social care throughout the life span; recognizing a coordinated, interdisciplinary treatment approach; focusing intervention on local and state levels; and encouraging coordination between university medical professionals and state provider agencies. This panel laid the structure for many important aspects of defining and treating developmental disorders in the next several decades.

Over the next three decades (1970–2000), the definition of developmental disabilities changed in scope and complexity. Most important, in 1975, Public Law 94–103 broadened the developmental disabilities definition to include autism and a few specific learning disabilities (e.g., dyslexia) if those learning disabilities related to existing and concurrent developmental disorders. The Developmental Disabilities Act (Public Law 95–605) of 1978 was a detailed explanation that set federal policy and state educational treatment for developmental disorders for many years to come. Newer definitions became less categorical and emphasized functional limitations. Use of the term impairment was also advocated and reference to disease was often removed.

Contemporary Issues in Defining Developmental Disorders

Contemporary research and practice for developmental disorders evolved with a more specific focus on components of learning difficulties, or subtypes of learning difficulties. Researchers primarily in the United States separated learning disorders from mental retardation and identified the components of learning disorders in children and adults. Attention focused on memory factors, attentional characteristics, and visual-spatial skills of the learner. In addition, there has been a move toward functional perspectives with particular developmental disorders or disabilities. This approach focuses on more discrete description of skills and adaptive behaviors that individuals need to perform in daily situations. In the past, often the relationship between specific medical diagnostic etiologies and learning disorders did not appear to capture what most individuals needed with respect to their instructional assistance and functioning.

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