Dementia in individuals with intellectual disability; is there a better way to diagnose?
The clinical utility of the Cognitive Computerised Test Battery for Individuals with Intellectual Disabilities and the Hopkins Verbal Learning Test.
Due to challenges in diagnosing dementia in individuals with an intellectual disability (ID), there is much disparity on which assessment tool should be used for diagnostics. The Cognitive Computerised Test Battery for Individual’s with Intellectual Disabilities (CCIID), is validated for use within ID populations, but was not yet tested for dementia assessment. The Hopkins Verbal Learning Test (HVLT) has been extensively used for dementia assessment in the general population; however, it has rarely been tested within an ID population. This study therefore aimed to assess whether the CCIID and HVLT could be used for dementia diagnostics for individuals with ID. ID dementia cases (n=7) were compared to ID controls (n=23) using Receiver Operating Curve (ROC) analysis to assess accuracy, sensitivity and specificity at baseline. A repeated measures analysis of variance then compared ID dementia cases (n=4) to ID controls (n=10) at 6 month follow-up. Results showed significant differences between cases and controls on total CCIID scores, CCIID Series subtest scores and total HVLT scores at baseline. ROC analysis indicated best accuracy, sensitivity and specificity for the Series test and the HVLT. However, systematic age differences within the sample showed that the HVLT was sensitive to age. This highlighted a need for further analysis into the effect of age on cognition for individuals with ID. In conclusion, this study presents evidence that suggests the Series subtest of the CCIID and the HVLT together could offer good potential in informing dementia assessment within ID populations. Future studies should seek to explore this further, as this study is limited by its small sample size.