Depression differentially affects patient and caregiver perceptions of neuropsychiatric symptoms in Parkinson's disease

Objective The aims of this study were twofold. First, we examined the relationship between patient and caregiver ratings of neuropsychiatric symptoms in Parkinson's disease (PD). Second, we examined if the severity of depressive symptoms affects patient and caregiver perceptions of other neuropsychiatric symptoms and contributes to discrepancies between their perceptions. Method We examined data from a retrospective clinical cohort of 209 patients with PD and their caregivers. We used intra-class correlation coefficients and the Bland Altman method to assess intra-respondent (retrospective versus current) and inter-respondent (patient versus caregiver) agreement between Frontal Systems Behavior Scales (FrSBe) subscale scores. We then used generalized estimating equation models to examine FrSBe subscale scores and the magnitude of the intra- and inter-respondent discrepancies in FrSBe subscale scores, as a function of Beck Depression Inventory-2(nd) Edition scores, with patient demographic variable adjustments. Results There was low agreement between patient and caregiver ratings on all three subscales, at both time points, and high response variability within and between raters. Patients generally reported more severe neuropsychiatric symptoms than caregivers. Depression severity predicted patients' perceptions at both time points, but was more strongly associated with current perceptions. Depression severity predicted caregivers' current perceptions only. The inter-respondent discrepancy in perceived apathy and disinhibition, but not executive dysfunction, increased as a function of depression severity. Conclusions There are differences in how patients with PD and caregivers perceive neuropsychiatric behaviors and the extent to which depressive symptoms influence their perceptions. Shared neuropathology and negative response biases likely contribute to these relationships.