Abstract
Alzheimer’s disease (AD) is a pervasive neurodegenerative disorder characterized by chronic neuroinflammation; current interventions primarily offer symptomatic relief. Cannabidiol (CBD), a non-psychoactive phytocannabinoid, exhibits multi-target therapeutic potential due to its established anti-inflammatory and neuroprotective properties. While growing interest exists, the evidence regarding CBD’s effects on AD-related neuroinflammation has not been robustly consolidated in a quantitative meta-analysis. Therefore, this article reviews the current literature around CBD related to its potential in alleviating neuroinflammation, followed by a meta-analysis of preclinical and clinical studies using random-effects modeling to assess CBD efficacy on neuroinflammation and clinical outcomes in AD. In preclinical AD models, the meta-analysis demonstrated that CBD significantly and consistently reduced key markers of neuroinflammation and reactive gliosis, specifically glial fibrillary acidic protein (GFAP) (p < 0.0001), Interleukin-6 (IL-6), and inducible nitric oxide synthase (iNOS). Effects on other markers, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β), were non-significant and heterogeneous. Clinical evidence, though limited by small sample size and heterogeneity, showed a borderline significant benefit favoring CBD for overall behavioral symptoms (p = 0.05), agitation, and caregiver distress. Adverse events were typically mild. We conclude that CBD demonstrates biologically consistent anti-inflammatory efficacy in preclinical AD models. While current clinical data remains insufficient to substantiate efficacy, they suggest promising signals for behavioral control. Determining CBD’s full therapeutic potential in AD necessitates future rigorous, mechanism-driven trials with standardized preparations and biomarker-anchored endpoints.