Social cognition and behaviour in dementia of the Alzheimer type

Abstract

Behaviour changes including apathy, disinhibition, irritability or social skills difficulties are commonly reported in individuals following an acquired brain injury (ABI) or presence of a neurodegenerative condition. In addition, there is evidence that these behaviour changes are related to increased caregiver burden and early nursing home and hospital admissions. Yet, very little is known about possible factors relating to behaviour change in ABI or neurodegeneration. Social cognition difficulties have been proposed as possible predictors of behaviour change in ABI or neurodegeneration. However, the evidence for the existence of a link between behaviour and social cognition remains weak. The aims of the current thesis were twofold; firstly, it aimed to systematically examine the current evidence on the link between social cognition and behaviour change in ABI or neurodegeneration. Secondly, the thesis aimed to assess the relationship between social cognition and behaviour change in the context of relationship quality in a sample of 27 individuals with a diagnosis of Dementia of the Alzheimer Type (DAT) or mixed DAT and vascular dementia and their co-residing partners. A review of the current literature showed a discrepancy in the evidence for an association between behaviour change and social cognition between ABI and neurodegenerative participant samples. The link between social cognition and behaviour changes in ABI, although suggested, was not found in the three included studies. However, this was not the case for neurogenerative samples. Although most of the included studies focused on a particular condition, frontotemporal dementia (FTD), evidence for this link was also present in one study focusing on DAT. Following from this review, the present thesis examined the existence of this association further in individuals with DAT/ mixed dementia. The study used partners’ reports on behaviour and relationship quality and examined their associations with individuals with DAT/mixed dementia’s performance on a social cognition task. Although the DAT/mixed dementia group showed an impaired performance on a social cognition task compared to their partners, there were no significant relationships between reported behaviour changes, relationship quality and social cognition performance in individuals with DAT/mixed dementia. These findings suggest that despite previous literature indicating a link between behaviour change and social cognition in DAT or mixed dementia, this relationship is yet to be fully established in this population and further research is needed to inform current practice and models of behaviour change in neurodegeneration. The present findings are also discussed with regards to implications for clinical practice and adaptations in psychotherapy for people with DAT or mixed dementia and their partners.