Lithium as a Treatment for Alzheimer's Disease: A Systematic Review and Meta-Analysis

Background: This is the first meta-analysis of randomized placebo-controlled trials testing lithium as a treatment for patients with Alzheimer's disease (AD) and individuals with mild cognitive impairment (MCI). Methods: The primary outcome measure was efficacy on cognitive performance as measured through the Alzheimer's Disease Assessment Scale cognitive subscale or the Mini-Mental State Examination. Other outcome measures were drug discontinuation rate, individual side effects, and biological markers (phosphorylated tau 181, total tau, and amyloid-β₄₂) in cerebrospinal fluid (CSF). Results: Three clinical trials including 232 participants that met the study's inclusion criteria were identified. Lithium significantly decreased cognitive decline as compared to placebo (standardized mean difference = -0.41, 95% confidence interval = -0.81 to -0.02, p = 0.04, I² = 47%, 3 studies, n = 199). There were no significant differences in the rate of attrition, discontinuation due to all causes or adverse events, or CSF biomarkers between treatment groups. Conclusions: The results indicate that lithium treatment may have beneficial effects on cognitive performance in subjects with MCI and AD dementia.