Behavioral symptoms of Alzheimer’s disease and autism spectrum disorder: Insights to guide future non‐pharmacological interventions

Abstract

AbstractBackgroundMany behavioral and psychiatric symptoms of dementia (BPSD) share similarities with those described in pediatric autism spectrum disorder (ASD), including anxiety, depression, and communication deficits. However, the possibility of late‐life onset of behaviors stereotypic of ASD in Alzheimer’s disease (AD) has been poorly explored. Findings of three studies are presented here to illustrate associations in behaviors between ASD and AD.MethodsCare partners of persons with cognitive impairment (MCI or dementia) from the University of Kentucky Alzheimer’s Disease Research Center community‐based longitudinal cohort were surveyed using the Gilliam Autism Rating Scale‐2 (GARS‐2). Analyses included t‐tests, chi‐square, analysis of variance, and linear regression models to explore frequency of ASD behaviors in this cohort, and the relationship of behaviors represented in the GARS‐2 compared to behavioral categories used in AD assessment (Neuropsychiatric Inventory‐Questionnaire; NPI‐Q). Lastly, cross‐sectional postmortem neuropathological analyses compared “Autism Possible” to “Autism Unlikely” in available cases.ResultsAnalyses included 142 GARS‐2 respondents. A substantial number of participants presented with ASD‐like behaviors, and those with high Autism Index scores had significantly younger age at onset (71.1±11.0 vs. 76.7±8.3; p = 0.034) and more severe cognitive impairment than those who scored in the “Autism Unlikely” range. ASD‐like behaviors were also significantly correlated with BPSD severity ratings (r = 0.47; p < 0.001). In neuropathological analyses, the two groups differed in the frontal and temporal regions, specific to tau pathology.ConclusionThese findings suggest that ASD‐like behaviors may emerge in AD as a result of shared neurological substrates, given that such behaviors are associated with an earlier age of onset and more severe cognitive impairment. With emerging evidence linking BPSD and ASD, additional research is needed to understand shared mechanisms, as well as development of novel treatment approaches to address behavioral symptoms of AD.