Comparative effectiveness of different non-invasive brain stimulation and lifestyle interventions on cognitive function in patients with Alzheimer’s disease or mild cognitive impairment: a systematic review and network meta-analysis

While non-invasive brain stimulation (NIBS) and lifestyle interventions have shown some potential for improving cognitive function in patients with Alzheimer’s disease (AD) and mild cognitive impairment (MCI), the comparative efficacy of different intervention measures remains unclear. This study aimed to compare and rank the beneficial effects of different NIBS and lifestyle interventions on improving global cognition and other specific cognitive domains in patients with AD or MCI. We systematically searched PubMed, Web of Science, Embase, the Cochrane Library, CINAHL, CNKI, VIP, Wanfang and SinoMed from inception to January 2026 for randomized controlled trials (RCTs). Patients with a diagnosis of AD or MCI were included. The primary outcome was global cognition, and the secondary outcomes were specific cognitive domains (executive function, language function, attention and memory function). Efficacy was assessed via standardized mean differences with 95% confidence intervals, and interventions were ranked via surface under the cumulative ranking curve (SUCRA) probabilities. All network meta‑analysis procedures were performed under the frequentist framework using Stata software. A total of 82 RCTs involving 6457 participants were included. Cognitive training (CT) might be the optimal intervention for global cognition (SMD = 0.81, 95% CI = 0.46 to 1.17). Additionally, repetitive transcranial magnetic stimulation (rTMS) might be the optimal intervention for executive function (SMD= -0.55, 95% CI= -1.03 to -0.07), exercise intervention (EI) might be the optimal intervention for language function (SMD = 0.46, 95% CI = 0.10 to 0.82), CT might be the optimal intervention for attention (SMD= -0.43, 95% CI= -0.83 to -0.04), and transcranial direct current stimulation (tDCS) might be the optimal intervention for memory function (SMD = 0.63, 95% CI = 0.31 to 0.96). Similar results were obtained in subgroup analyses of global cognition in patients with MCI and AD. Our study confirmed the different effectiveness of NIBS and life interventions for improving global cognition and specific cognitive domains. Moreover, it provides evidence-based support for the formulation of rehabilitation measures for MCI and AD patients in clinical settings. However, since several intervention methods are understudied, more high-quality RCTs are needed in the future to clarify their specific therapeutic effects.