My PhD examined plasma biomarkers of tau dysregulation, neuroinflammation, and neurodegeneration in Alzheimer’s disease, evaluating their relationships with cognitive and functional outcomes to enhance diagnostic and prognostic precision. To achieve this, as Principal Investigator I designed and conducted The SAMe Study, a world-first phase II, multi-centre, randomised, double-blind, placebo-controlled trial of S-adenosyl methionine (SAMe) as a potential tau-modifying therapy. Alongside assessing SAMe’s therapeutic effects, I analysed real-world trial biomarker data to determine what these measures revealed about patient function and clinical outcomes, including cognitive performance. Collectively, this work aims to advance the development of accessible, clinically useful plasma biomarkers for Alzheimer’s disease.