Neuropsychiatric Symptoms in Major Neurocognitive Disorder: Associations with Caregiver Burden and Sleep Quality

Background: Neuropsychiatric symptoms (NPSs) are among the most clinically disruptive manifestations of major neurocognitive disorder (MND) and major contributors to caregiver distress. However, the differential contribution of specific neuropsychiatric domains to caregiver burden and sleep quality has remained insufficiently characterized. Methods: This single-center retrospective observational study included 164 patient–caregiver dyads. Patients were diagnosed with MND according to DSM-5 criteria. NPS were assessed using the Neuropsychiatric Inventory (NPI-Q). Caregiver burden and sleep quality were evaluated using the 12-item Zarit Burden Interview (ZBI-12) and the Pittsburgh Sleep Quality Index (PSQI), respectively. Beta and logistic regression models were applied to investigate associations between NPS severity and caregiver outcomes after adjustment for cognitive and functional status. Additional analyses explored the relative contribution of individual NPI-Q subdomains. Results: Greater overall NPS severity was significantly associated with both increased caregiver burden (β = 0.163, p < 0.001) and altered caregiver sleep quality (OR = 1.32, 95% CI: 1.12–1.59, p = 0.002). Clinically significant sleep disturbances (PSQI > 5) were observed in 61.6% of caregivers. Among NPS, delusions showed the strongest association with caregiver burden (β = 0.329, p < 0.001), followed by depressive symptoms (β = 0.156, p = 0.004) and irritability (β = 0.147, p = 0.005); furthermore, sleep and night-time behavior disorders emerged as the strongest contributors to altered caregiver sleep quality (p < 0.001). Conclusions: Greater NPS severity may be associated with increased caregiver burden and poorer sleep quality in caregivers of patients with MND. Different NPSs appear to be differentially associated with caregiver outcomes, despite the lack of caregiver-level covariates, supporting the need for multidimensional and caregiver-centered approaches in dementia care. Given the exploratory nature of these analyses, these findings should be interpreted as descriptive rather than confirmatory.