John T. O'Brien

Professor John T. O'Brien serves as Professor of Old Age Psychiatry in the Department of Psychiatry at the University of Cambridge's School of Clinical Medicine. He holds dual clinical appointments as Honorary Consultant Old Age Psychiatrist at Cambridgeshire and Peterborough NHS Foundation Trust and Cambridge University Hospitals NHS Trust. His leadership extends to the Old Age Psychiatry Research Group and the Neuroimmunology theme within Dementias Platform UK's Experimental Medicine Incubator.

His research focuses on advancing dementia diagnostics and management through multi-modal imaging (MRI, MEG, PET), fluid biomarkers, and clinical trials. Key interests include:

• Pathophysiological mechanisms in Lewy body dementia and Alzheimer's disease
• Vascular contributions to dementia and late-life depression
• Prodromal and preclinical stages of neurodegenerative disorders
• Noradrenergic and immunosuppressive therapies for Parkinson-plus syndromes

His publication analysis reveals consistent emphasis on biomarker development across 450+ peer-reviewed papers, with recent work prioritizing inflammation imaging (Work Package 27c) and immunoprofiling in prodromal dementia (Work Package 27b).

Key recognitions include:

• Election as Fellow of the Academy of Medical Sciences
• NIHR Emeritus Senior Investigator status
• Leadership roles in ICGP and International Vas-Cog Society

He actively contributes to national dementia strategy as NIHR National Specialty Lead for Dementias and participates in guideline development for NICE, BAP, and EFNS. His research collaborations span the Cambridge Biomedical Research Centre, Dementias Platform UK, NIHR Dementia Translational Research Collaboration, European DLB Group, and International DLB Consortium.

O'Brien directs the Old Age Psychiatry Research Group at the Cambridge Biomedical Campus, coordinating cross-departmental initiatives with Clinical Neurosciences and leveraging resources from the Cambridge University Hospitals NHS Foundation Trust.