Comorbid Symptomology in Adults with Autism Spectrum Disorder and Intellectual Disability.
Adults with ASD plus severe ID carry extra psychiatric baggage—screen broadly and often.
01Research in Context
What this study did
The team compared the adults who had both autism and severe or profound intellectual disability with the adults who had ID only.
They used caregiver interviews and chart reviews to count symptoms in eight areas: anxiety, mood, psychosis, impulse control, sleep, self-injury, stereotypy, and elimination problems.
All adults lived in 24-hour staffed homes in Victoria, Australia.
What they found
The ASD+ID group had more symptoms in every area.
Biggest gaps were anxiety, self-injury, psychosis, and impulse control.
Effect sizes were large, so the difference is clinically meaningful, not just statistically significant.
How this fits with other research
McCauley et al. (2018) saw the same pattern in kids: ASD+ID lowered quality of life in social and physical domains compared with ID-only.
Supekar et al. (2017) adds a time lens—ADHD and epilepsy rates drop after adolescence, while schizophrenia risk rises in older ASD males.
Holburn (2001) warns that hidden hearing or vision loss can mimic psychiatric problems in ID clients, so check senses before labeling behavior.
Together the papers show the ASD+ID combo brings heavier and shifting clinical loads across the lifespan.
Why it matters
When an adult with both diagnoses walks in, expect more than ID. Screen for anxiety, self-injury, psychosis, and impulse issues right away. Add vision and hearing checks to rule out sensory drivers. Update the behavior plan as the person ages—what you see at 25 may look different at 45.
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02At a glance
03Original abstract
Evidence-based treatment must begin with the systematic and comprehensive identification of an individual's complete clinical picture. Therefore, screening individuals with intellectual disability (ID) for comorbid disorders is imperative. Because of the frequent overlap between autism spectrum disorder (ASD) and ID, the current study explored the effects of co-occurring ASD on the comorbid symptoms exhibited by adults with ID. The study included 307 adults with severe or profound ID separated into two groups: ASD+ID and ID only. The ASD+ID group exhibited significantly more symptomology on eight of the 12 subscales examined including anxiety, mania, schizophrenia, stereotypies/tics, self-injurious behavior, eating disorders, sexual disorders, and impulse control. Further, comparisons of specific symptom endorsements yielded distinct results.
Journal of autism and developmental disorders, 2015 · doi:10.1007/s10803-015-2553-z