(Medical Xpress) -- A commentary published in the April issue of the Journal of the American Academy of Child & Adolescent Psychiatry reviews the significant limitations of a study critical of the proposed diagnostic criteria for autism spectrum disorder (ASD). The criteria are being proposed for the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).
The commentary, by the 13 members of the DSM-5 Neurodevelopmental Disorders Work Group, addresses serious methodological flaws in the secondary analysis of an 18-year-old study by McPartland et al, who attempted to evaluate the proposed new diagnostic criteria for ASD and their potential impact on children with high-functioning autism.
The Work Group members state: ―We believe the archived data used in these analyses have too many inherent limitations to assess the criteria proposed for the DSM-5, particularly in regard to sensitivity and specificity.‖ Those limitations stem from the study sample dating to 1994 and the restrictive way data from that sample were collected and evaluated. They make any legitimate review and comparison virtually impossible and ―justify neither alarming headlines nor dramatic conclusions.
The Work Group has proposed that autism, Aspergers disorder, pervasive developmental disorder (not otherwise specified) and childhood disintegrative disorder be consolidated within the overarching category of ASD. The change signals how symptoms of these disorders represent a continuum from mild to severe, rather than being distinct disorders. The new category is expected to help clinicians more accurately diagnose people with relevant symptoms and behaviors by recognizing the differences from person to person, instead of providing general labels that tend not to be consistently applied across different clinics and centers.
Developing more useful diagnostic criteria for clinicians and individuals with ASD has been the core objective of the Work Groups efforts. For example, the proposed measures indicate increased sensitivity in regard to age of onset. DSM-IV requires functioning delays to be present prior to age 3; DSM-5 criteria would extend this until ―social demands exceed limited capacities,‖ as long as symptoms were present in early childhood. Despite what some critics have suggested, the issue of containing autism rates was not considered by the Work Group, nor was it a factor in revising the criteria.
The commentary notes: ―The answer to the most important question, Have we succeeded in accurately capturing all individuals with ASD with the diagnostic criteria proposed for DSM-5, is not yet known.‖ Preliminary data examined as part of the Work Groups continuing review have indicated that the criteria would be both sensitive and specificrather than one benefiting at the expense of the otherbut further analyses using data from the recently completed DSM-5 field trials are under way.
David Kupfer, M.D., chair of the DSM-5 Task Force, praised the Work Group for extraordinarily thorough, thoughtful and detailed work. ―We remain open to any concerns the academic and advocacy communities might have, but we strongly support the decisions that these leading researchers and clinicians have made,‖ Kupfer said. ―The proposed ASD criteria are backed by the scientific evidence.
DSM-5, which is published by the American Psychiatric Association, is used by health care professionals in the United States and much of the world as the authoritative guide to the diagnosis of mental disorders. Its latest proposed diagnostic criteria for ASD and all other disorders are available on www.dsm5.org .
Release of DSM-5 is scheduled for May 2013, culminating a 14-year revision process.