Implementation and service impact of anti-amyloid therapy in a psychiatry-led dementia care program: Real-world evidence from a Japanese regional dementia center.

BACKGROUND

Amyloid-targeting antibody therapies for Alzheimer's disease require substantial diagnostic infrastructure including amyloid PET imaging, repeated MRI monitoring, and specialized clinical evaluation. In Japan, psychiatrists frequently lead dementia diagnosis and treatment in general hospitals through designated Regional Dementia Medical Centers; however, the real-world service impact of implementing these therapies in psychiatry-led dementia care remains poorly described.

METHODS

We conducted a retrospective analysis of administrative and billing data from a Regional Dementia Medical Center at Kakogawa Central City Hospital, Japan. Data included amyloid PET imaging, anti-amyloid monoclonal antibody therapy (lecanemab and donanemab), and associated reimbursement and acquisition costs between May 2024 and January 2026. This study was conducted as part of institutional quality improvement activities.

RESULTS

During the observation period, 72 amyloid PET examinations were performed. Results were amyloid-positive in 50 cases (69%) and negative in 22 cases (31%). Of 50 amyloid-positive patients, 38 (76%) initiated anti-amyloid therapy (lecanemab: 14; donanemab: 24), with 389 total treatment administrations. ARIA was detected in 8 treated patients (21%), all asymptomatic. MRI examinations for ARIA monitoring increased from 5 in FY2023 to 58 in FY2024 and 139 in FY2025. Total reimbursement amounted to 35.4 million yen for lecanemab and 25.7 million yen for donanemab. Drug acquisition costs represented approximately 97% of reimbursement, with margins averaging 3%. Outpatient revenue per visit increased 141% from 5560 yen in FY2022 to 13,401 yen in FY2025, despite stable visit volumes (FY2022: 11,203; FY2024: 10,223).

CONCLUSIONS

Implementation of amyloid-targeting antibody therapy in psychiatry-led dementia care substantially increases service activity and hospital revenue streams but generates narrow financial margins due to high drug acquisition costs. All ARIA cases were asymptomatic, supporting the feasibility of systematic monitoring within a psychiatry-led model in this setting. These findings highlight important structural and economic considerations for the sustainability of these programs in general hospital psychiatry.