Asperger's syndrome and non-verbal learning disabilities: A study of differential diagnosis agreement across disciplines
Mental health professionals tend to have a clinical perspective that is dependent upon Diagnostic and Statistical Manual of Mental Disorders-IV-TR (DSM-IV) criteria for a differential diagnosis. School-based clinicians are bound by regulations governing special education placement established by Individuals with Disabilities Education Act (IDEA). While both sets of clinicians generate diagnostic recommendations for students, the guidelines and criteria are not of parallel descriptors. AS is only a diagnosis provided for in DSM-IV. Non-verbal learning disability (NVLD) and high functioning autism (HFA) are addressed in both DSM-IV and IDEA. The dilemma presented to clinicians is intertwining the terminology of both fields in order to provide a more concise and meaningful diagnosis for the students who are being served.
Although school-based and mental-health clinicians provide services for students, the criteria employed may differ. Essentially, the descriptors that are applied to Asperger's Syndrome (AS) and NVLD are similar and may only differ in the criteria used by different discipline affiliations. Upon review of the literature, there seems to be some question about the different clinical perspectives and diagnosis that may emerge. The criteria used for disability identification is often based upon discipline affiliation. Bashe and Kirby (2000) suggest that psychiatrists may identify students with AS while an education-based organization might suggest a learning disability and yet, a speech and language pathologist might refer to the same set of characteristics as a semantic-pragmatic disorder or an audiologist would refer to a central auditory processing disorder. Furthermore, Bashe and Kirby felt that the “specialist” generally sees and identifies the facet of AS that pertains to their area of expertise. While identification is a critical component of planning intervention, service delivery of both AS and NVLD students are relegated to educators and the school-based program. Therefore, the terminology employed to identify a disability must be applicable to the school setting.
The literature often refers to AS in a hyphenated context with HFA. Rather than there being a consistent diagnostic category of AS, AS is often joined with HFA as a means of describing symptoms that transcend characteristics of autism but still have similarities with students classified as having autism. There is also a considerable amount of literature that differentiates the two terms and refers to AS and HFA as two distinct disabilities. Furthermore, there is a great deal of conjecture regarding AS as a type of learning disability. This study will ascertain whether there is agreement between disciplines in diagnosis of AS and NVLD, whether or not there is consistency between and among disciplines regarding the importance of specific characteristics of the two disabilities, and the application of these characteristics when rendering a diagnosis and intervention recommendations.
While the results of this study did not demonstrate an interaction between diagnosis and professional discipline affiliation, it did demonstrate that the rate of correct diagnosis for AS was significantly higher than that of NVLD and autism. An alternative conclusion is that AS is overly diagnosed and impacting the rate of correct diagnosis for NVLD and autism. While there was an association between the elements used for clinical diagnosis of both autism and AS, there was a demonstrable correlation of service delivery models for both NVLD and AS and a departure of similarities in service delivery between AS and autism. Implications of these results are discussed in greater detail.
0288: Educational evaluation
0632: Psychological tests