Executive and Social-Cognitive Determinants of Environmental Dependency Syndrome in Behavioral Frontotemporal Dementia

Objective: Environmental dependency syndrome (EDS), including utilization (UB) and imitation (IB) behaviors, is often reported in behavioral variant frontotemporal dementia (bvFTD). These behaviors are commonly attributed to executive dysfunction. However, inconsistent associations between EDS and poor executive performance has led to an alternative "social hypothesis," instead implicating patients' misinterpretation of the examiner's intention. We investigated the possible explanatory cognitive mechanisms of EDS in bvFTD by relating UB and IB to performance on tests of executive functioning and theory of mind (ToM). Method: This study analyzed retrospective data of 32 bvFTD patients. Data included scores of UB and IB, various executive measures, and ToM assessment using the faux pas test, from which we extracted a mental attribution score. Results: Of the patients, 15.6% and 40.6% exhibited UB and IB, respectively. We conducted an automatic linear modeling analysis with executive and mental attribution measures as predictor variables, and UB and IB sequentially considered as target variables. ToM mental attribution score, visual abstraction and flexibility measures from the Wisconsin Card Sorting Test, and motor sequence performance significantly (corrected ps < .05) predicted IB. No executive or ToM measures significantly predicted UB. Conclusions: These findings reveal a complex interaction between executive dysfunction and mental attribution deficits influencing the prevalence of EDS in bvFTD. Further investigation is required to improve our understanding of the mechanisms underlying these behaviors. General Scientific Summary Environmental dependency syndrome (EDS) is a group of pathological behaviors that have been reported after frontal lesion/degeneration. Typically, patients use objects without having been asked to do so or imitate an examiner's gestures during a clinical examination. The reasons for the presence of such behavior are poorly understood, and this study aimed to understand their cognitive origin and whether EDS could be attributed to disinhibition or to a failure to infer the examiner's expectations.