40% Intellectual Disability In Autism Disorders: Coincidence or Consequence?

I have never subscribed to the assumption that Intellectual Disability is a co-morbidity as described by the authors of a new study examining Intellectual  Disability in Autism: (unrelated in etiology and causality from the ASD itself)  I have been frustrated by the historical tendency of  "autism" researchers to exclude intellectually disabled autistic subjects from their research studies.  I am very disappointed with Dr. Lord, Dr. Swedo, Dr. King and other APA members for their efforts to further the artificial disassociation of Intellectual Disability from Autism Spectrum Disorder (s) in the DSM5.  I have always believed, as the father of a severely autistic son with "profound developmental delay", and contrary to the "autism as strength" ideology of Dr. Laurent Mottron and Michelle Dawson, that autism and intellectual disability are inseparable components of my son's condition. I am very pleased to see reports of a new study, as set out in this brief online paper by the authors of that study, which begins to examine the ID and ASD relationship front on and with complete intellectual honesty.  

I hope that the proof of principle resulting from the study  that "ASD symptom severity contributes to the extent to which the environmental input required to support “typical” brain development can be processed by the individual, so that the risk of developing ID increases as the number and severity of ASD social-communicative impairments increase"  is pursued further and that additional research on this topic is not squelched by the political correctness of those who control autism research funding dollars.

I also hope that researchers study the ID in ASD issue from  different perspectives:  that the ID increases the severity of the ASD symptoms and that ID and ASD are simply different aspects of one condition.   This humble father  does not believe that my son's severe autism symptoms and ID are separate coincidental or "comorbid" conditions.  I am pleased to see these "down under" Austalian researchers joining the ranks of the few with the intellectual honesty and curiousity to study the Intellectual Disability component of autism symptoms and disorders.

Intellectual development in autism spectrum disorders: new insights from longitudinal studies

Giacomo Vivanti^1,2*, Josephine Barbaro¹, Kristelle Hudry¹, Cheryl Dissanayake¹ and Margot Prior^1,3

•   ¹Olga Tennison Autism Research Centre, School of Psychological Science, La Trobe University, Melbourne, VIC, Australia
•  ²Victorian Autism Specific Early Learning and Care Centre, La Trobe University, Melbourne, VIC, Australia³
• ³ Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, VIC, Australia

The presence/absence of Intellectual Disability (ID) is considered to be the most critical factor affecting outcomes in individuals with Autism Spectrum Disorders (ASD). However, the question of the specific nature of ID in ASD has received little attention, with the current view being that ID is a comorbid condition (i.e., one that is unrelated in etiology and causality from the ASD itself). Recent advances in developmental neuroscience, highlighting the importance of early exposure to social experiences for cognitive development, support an alternative view; that ID in ASD might emerge as a consequence of severe social-communication deficits on the experience-dependent mechanisms underlying neurocognitive development. We tested this prediction in two independent samples of young children with ASD (Ns = 23 and 60), finding that children with greater ASD severity at an initial assessment were more likely to present with poorer cognitive outcomes at a later assessment, irrespective of initial cognitive level. The results of this proof of principle study suggest that ASD symptom severity contributes to the extent to which the environmental input required to support “typical” brain development can be processed by the individual, so that the risk of developing ID increases as the number and severity of ASD social-communicative impairments increase.