Six-month randomized, double-blind trial of transcranial direct current stimulation in mild Alzheimer's dementia: domain-specific cognitive and neuropsychiatric signals

Background: Prefrontal transcranial direct current stimulation (tDCS) is a low-risk candidate intervention for cognitive enhancement in Alzheimer's disease (AD), but trial results are heterogeneous and often short-term. We evaluated the 26-week efficacy, safety, and family-level impact of home-based prefrontal tDCS in mild AD. Methods: = 61) tDCS. The intention-to-treat (ITT) population included 106 participants (53 vs. 53) with post-baseline data; 66 (32 vs. 34) comprised the per-protocol (PP) set. The primary outcome was change in global cognition on the Korean Mini-Mental State Examination (K-MMSE). Secondary and exploratory outcomes included domain-specific cognition [e.g., Korean Boston Naming Test (K-BNT)], neuropsychiatric symptoms [Korean Neuropsychiatric Inventory (K-NPI)], patient quality of life (QoL-AD), and caregiver-reported family quality of life [Family Quality of Life-Dementia (FQoL-D)]. Adverse events (AEs) were systematically monitored. Overall AE rates were similar; stimulation-site reactions were common but mild, and serious AEs were rare and deemed unrelated to tDCS. Conclusion: In mild AD, 26 weeks of home-based prefrontal tDCS did not improve global cognition vs. sham, although a modest benefit in confrontation naming was observed. The deterioration in caregiver-reported family quality of life highlights the need to weigh potential cognitive gains against family burden in long-term home-based neuromodulation. Clinical trial registration: Clinical Research Information Service (CRIS), KCT0005834.