Trends in Autism and Specific Learning Disabilities (SLD) in Kentucky, 1981-2005

Objective: The primary purpose of the study is to describe the epidemiology of Autism in Kentucky. The secondary purpose is to describe the trends of Specific Learning Disability (SLD) and Autism from 1981-2005.

Design: This study used secondary data from Kentucky Department of Special Education. Data contains information on the prevalence of various developmental disorders for each academic year from 1981 to 2005.

Main Outcome: Prevalence of SLD which was in epidemic proportions in 1980's and in early 1990's, drastically decreased with reporting of Autism from 1992. This decrease could not be explained as there was no change in Diagnostic criteria of SLD from 1981 to 2005 and there is no specific preventive program which aims to decrease the prevalence of SLD.

Results: Child count with Autism increased from 53 cases in the year 1992 to 2068 cases in the year 2005 (3801.89 % increase). Child count with SLD dropped from 23,302 cases in the year 1992 to 15,341 cases in the year 2005 (34.16 % decrease). The child count with SLD increased from 1981 (18,046 cases) to 1992 (23,302 cases) and then started to decline gradually.

Conclusion: Autism, which was non-existent in Kentucky before 1992, has risen to epidemic proportions presently. The reasons for such an increase may be due to increased awareness, change in diagnostic criteria, inclusion of a separate category for Autism, wrong diagnosis and diagnosis by non-physicians. It is imperative to learn about the true causation of the disproportionate growth of Autism and decrease in SLD.