Low serum serotonin is associated with functional decline, mild behavioural impairment and brain atrophy in dementia-free subjects

• DOI: 10.1093/braincomms/fcaf005
• Publication Date: 2025-01-09T15:06:24Z
• Authors: Ming Ann Sim; Yingqi Liao; Siew Pang Chan; Eugene S J Tan; Cheuk Ni Kan; Joyce R Chong; Yuek Ling Chai; Narayanaswamy Ven...; Boon Yeow Tan; Saima Hilal; Xin Xu; Christopher L H Chen; Mitchell K P Lai
• Keywords: Functional impairment

Abstract Brain serotonin dysregulation is associated with dementia and neuropsychiatric symptomology. However, the prognostic utility of circulating levels in detecting features prodromal including functional decline, cognitive impairment, mild behavioural impairment brain atrophy remains unclear. In this prospective study memory clinic subjects followed-up for ≤5 years, dementia-free subjects, classified as having no or at baseline, underwent annual neuropsychological assessments Montreal Cognitive Assessment, Global Cognition Z-scores Clinical Dementia Rating Scale Scores (where a ≥ 0.5 increment from baseline denotes decline). Mild was measured using Neuropsychiatric Inventory assessments, while evaluated cortical medial temporal scores MRI scans. Baseline serum then neuroimaging measures cross-sectionally longitudinally. Furthermore, associations cross-sectional were studied. Of 191 elderly included study, 63 (33.0%) had 128 (67.0%) dementia. Fourteen (9.0%) showed impairment. Compared highest tertile, within lowest tertile greater Cortical Atrophy (adjusted odds ratio = 2.54, 95% confidence interval=1.22–5.30, P 0.013). Serotonin not significantly (all > 0.05). 181 longitudinal follow-up (median duration 60.0 months), 56 (30.9%) developed incident occurred 26/119 (21.8%) subjects. lower higher hazards decline (lowest tertile: adjusted 2.15, interval 1.04–4.44, 0.039), 3.82, 1.13–12.87, 0.031, middle 3.56, =1.05–12.15, 0.042). The association between mediated via its effect on 3.96, 1.15–13.61, 0.029). conclusion, low may be well act an early marker elderly,