Why

Autistic people are often underrepresented in autism research, which usually relies on reports from parents, teachers and clinicians. Self-report methods, like interviews and surveys, often exclude individuals with intellectual disability, who make up around 31–50% of the Autistic population. While involving Autistic individuals and their families in research has grown and shown benefits, it’s unclear if this includes studies focusing on those with intellectual disability. A systematic review is needed to understand the research done so far, improve inclusivity, and guide future studies with better, more inclusive methods.

How much research uses first-hand information from Autistic people with intellectual disability? What measures have been used?

The research

We conducted a systematic search of six major databases from January 2013 to July 2023, focusing on studies involving Autistic adults with intellectual disability. To qualify, studies needed at least 70% of participants to be Autistic adults with intellectual disability and include at least one self-report measure. After screening 4,451 articles and reviewing 277 full texts, 263 were excluded for reasons such as not meeting the 70% threshold, lacking self-report measures, or focusing on children. Ultimately, 14 studies met the inclusion criteria for the systematic review.

Publication

Gibbs, V., Cai, R.Y., Love, A.M., Edwards, C., & Al Ansari, M. (2024). Unheard Voices: A Systematic Literature Review of Studies Using Self-Report Methods to Gather the Perspectives of Autistic Adults with Intellectual Disability. Autism in Adulthood.

Making a difference

Our review highlights major gaps in autism research, especially the lack of focus on Autistic adults with intellectual disability. Despite growing efforts to include Autistic voices, those with intellectual disabilities remain largely excluded. Future research should develop accessible self-report tools and involve these individuals to better reflect the full diversity of Autistic experiences and create meaningful outcomes for this underserved group.

Research team

Dr Vicki Gibbs, Aspect Research Centre for Autism Practice (ARCAP)

Dr Abbey Love, ARCAP

Dr Ru Ying Cai, ARCAP

Dr Chris Edwards, ARCAP

Dr Mustafa Al Ansari (ARCAP/La Trobe University)

Funding

Aspect