Abstract
Since Kanner's classic description of the syndrome of early infantile autism in 1943, conceptions of the disorder have evolved while retaining important continuity with what Kanner viewed as the hallmarks of the condition-social impairment (autism) and difficulties in dealing with change in the nonsocial world (insistence on sameness). This paper reviews the history of this evolution and the important potential advantages and disadvantages of changes being contemplated for DSM-5. The convergence of diagnostic approach in DSM-IV and ICD-10 provided a shared system that fostered a tremendous body of research. The changes proposed in DSM-5 may impact both research comparability and service eligibility.