Background Both mild cognitive impairment (MCI) and mild behavioural impairment (MBI) represent pre‑dementia at‑risk states; however, their broader social impacts regarding healthcare utilisation and economic burden remain understudied. This study estimated the service utilisation patterns and associated economic costs of MCI, with and without neuropsychiatric symptoms (NPS), among community‑dwelling older adults in a Chinese population.

Methods Using data from a population‑based prevalence survey of neurocognitive disorders in Hong Kong, 411 older adults aged ≥60 were included in the cost analysis (no MCI/NPS: 116; NPS only: 37; MCI only: 188; MCI+NPS: 70). NPS were defined as the presence of more than two symptoms on the Neuropsychiatric Inventory or a documented history of common mental disorders. Service utilisation, including medical, social, and informal care, was assessed using the Resource Utilisation in Dementia questionnaire. Per‑person annual costs were estimated from a societal perspective in 2022 US dollars. Group differences were examined using analysis of variance and regression analysis.

Results Annual per‑person costs increased with the presence of NPS and cognitive decline: no MCI/NPS (US$3,519; SD 4,398), NPS only (US$3,849; SD 3,592), MCI only (US$5,305; SD 5,140), and MCI+NPS (US$6,362; SD 7,260). Compared with normal control, participants with MCI incurred significantly higher healthcare costs (primarily due to greater emergency and outpatient service use) and higher informal care costs (P<0.05). Relative to the MCI‑only group, those with comorbid MCI and NPS experienced an additional increase in health care costs, also driven by emergency and outpatient utilisation (P<0.05). Although not statistically significant, a rising trend in social care utilisation was observed among individuals with MCI and/or NPS.

Conclusions MCI and NPS substantially increase healthcare and informal care costs in older adults, with the greatest burden occurring when both conditions are present. These findings underscore the importance of early detection and management of behavioural and cognitive changes in ageing populations. Further research is warranted to understand how healthcare utilisation evolves alongside changes in behavioural and cognitive status over time.