Assessment of Cognition in People with Intellectual Disabilities Using a Novel Set of Neuropsychological Tests

Background: There is no ‘gold standard’ for identifying dementia in people with an intellectual disability, which hinders access to early identification and appropriate support to members of this community. Differences in executive functioning may mean widely used cognitive assessments and tests are not accessible, acceptable, or feasible for use with people with intellectual disabilities. A literature review highlighted 114 available stand-alone measures and 37 batteries used to measure cognitive decline in people with an intellectual disability. Many did not show robust assessment of executive function and showed floor effects for people with more severe cognitive impairments. Research showed tests of olfaction may be an accessible format for use with people with intellectual disabilities.

Methods: Responding to the need highlighted through the literature review, a novel draft cognitive battery was created, which included robust assessment of executive functions, and an olfactory measure of learning and memory. An exploratory method was adopted to assess feasibility and acceptability by piloting the battery with four people with Down Syndrome. Quantitative data were gathered through test performance, and qualitative data were collected through participant feedback and researcher observation.

Results: Results indicated acceptability and feasibility of the battery for use with people with Down Syndrome, but many items require modification. Feasible tests of executive function proved most challenging to create, aligning with the literature. Implications for olfactory assessment with people with intellectual disabilities were identified.

Conclusions: Results identify recommendations for revisions to the battery and candidate tasks which may improve feasibility and acceptability. The importance of gathering the opinions of people with intellectual disabilities to shape instruments for their care is highlighted. Results inform future piloting with larger and more diverse samples from the intellectual disability community.