Diagnostic and Statistical Manual of Mental Disorders

The Diagnostic and Statistical Manual of Mental Disorders (DSM), published by the American Psychiatric Association (APA), is used for the diagnosis and classification of mental illness and intellectual disabilities. This entry provides information regarding changes in the APA classification scheme from the first manual to the fifth edition, issued in 2013, as well as changes in the classification of intellectual disabilities over the course of time.

Early in the 20th century, North American medical and psychology practitioners recognized the need for a standardized classification system of mental disorders. Prior to this observation, practitioners and researchers defined and classified disorders in a manner that suited their needs. This lack of standardization resulted in communication problems with regard to interdisciplinary and intradisciplinary collaborations and made it difficult to ...