Poster Presented at the 112th Annual Convention of the American Psychological Association, Honolulu, HI Factors Influencing School Psychologists ’ Diagnosis of Asperger’s Disorder and Autism

School psychologists play an important role in the diagnosis of pervasive developmental disorders, including Asperger’s Disorder and Autism (Harris & Glasberg, 1996). Differential diagnosis of these disorders may present unique challenges for school psychologists and for special education practice (Safran, 2001). Since the inclusion of Asperger’s Disorder (AsD) in the DSM-IV, there has been considerable controversy over the current criteria for differential diagnosis of AsD and Autistic Disorder (AuD). Despite differentiating criteria specified in the DSM-IV (e.g., language delay, cognitive delay), there is considerable overlap in the criteria for each disorder and several researchers have questioned the validity of the DSM-IV classification of AsD and AuD (Mayes, Calhoun, & Crites, 2001; Tanguay, Robertson, & Derrick, 1998). One common criticism of the current criteria for AsD is that the distinguishing characteristics listed in the DSM-IV have not been empirically supported. For instance, the DSM-IV operationally defines significant language delay in terms of developmental milestones. However, research has failed to support the discriminant validity of this language delay criterion (Mayes & Calhoun, 2001). Substantive concerns have also been raised over the DSM-IV criteria pertaining to the nature of differences between AsD and AuD in cognitive development, stereotyped or restricted patterns of behavior, and social interaction. Moreover, the DSM-IV criteria neglect the interactive nature of the core symptom areas of AsD and AuD (Kugler, 1998). Consequently, if clinicians adhere strictly to the DSM-IV criteria, it is virtually impossible to make a diagnosis of AsD (Mayes & Calhoun, 2001). Several studies have documented that most children who receive a diagnosis of AsD should or could have been diagnosed with AuD, suggesting that clinicians must be basing their diagnosis on criteria other than those specified in the DSM-I