Professor John O’Brien leads the Old Age Psychiatry Research Group which is part of the Department of Psychiatry at the University of Cambridge. His own research focusses on the study of dementia, especially Lewy body dementia, and uses a number of methodologies to try to improve the diagnosis and management of these disorders. In particular, utilising multi-modal imaging with MRI, MEG and novel PET and fluid markers to study pathophysiological processes and develop biomarkers for diagnosis and disease progression, and conduct clinical trials to improve patient management.