Comparing Math LD Diagnostic Rates Obtained Using LDAC and DSM-5 Criteria: Implications for the Field:

Within the Canadian context, the two major learning disability classification systems are arguably the American Psychiatric Association's (APA) Diagnostic and Statistical Manual of Mental Disorders and the Learning Disabilities Association (LDAC) of Canada's Official Definition of Learning Disabilities. Several of the more recent changes to the fifth edition of the DSM contrast with the LDAC definition, which establishes them as competing diagnostic frameworks. We investigated the frequency of math learning disability identification when both the LDAC and DSM-5 criteria were modelled and applied to an archived data set (2011-2016). Results support generally similar percentages of math learning disability cases identified when employing LDAC or DSM-5 criteria; however, the two methods identified a different set of cases. Implications for using DSM-5 versus LDAC criteria in diagnosing learning disabilities are discussed, including the need to consider adopting a national diagnostic standard.