Background: The neuropsychiatric complications of Parkinson's disease (PD), which include behaviour disturbances such as apathy and the impulse control disorders (ICDs), may have a significant effect on patients with PD and their carers. The contribution of these behaviour disorders to carer burden is less understood. Therefore, the aim of this study was to explore the relationship that apathy and ICDs have with carer burden.
Methods: Non-demented (n = 71) PD–carer dyads (spouse or adult child) participated in the study. The PD participants were divided into three behavioural groups: ICD (n = 21), apathy (n = 22) and controls (n = 28). The three groups were compared for level of burden in their carers by using the Zarit Burden Interview. The PD participants were rated for levels of apathy, impulsivity and motor and psychiatric symptoms. Using a multivariate analysis, we sought the PD-related predictors of carer burden.
Results: Significantly, greater burden was seen in carers of PD participants with ICDs (p = 0.002) or apathy (p = 0.004), compared with carers of PD participants without such behavioural disturbances. Linear regression models revealed that attentional ability accounted for burden in carers of the group with apathy, whereas dopaminergic load and depression accounted for burden in carers of the group with impulsivity.
Conclusion: PD-related behaviour disturbances, such as apathy and ICDs, as well as psychiatric complications, have significant negative implications for burden of care.