Alasdair MacLullich is Professor of Geriatric Medicine at the University of Edinburgh in Scotland. He is trained in medicine and psychology. Following a PhD in cognitive ageing he became Lecturer then MRC Clinician Scientist Fellow before taking up his present post. Alasdair works clinically (50%) in acute geriatrics and orthogeriatrics. His research interests include the clinical and neuropsychological assessment of delirium, delirium treatment, neuroimaging of delirium, and the pathophysiology of delirium. He is the main author of the 4AT delirium detection tool (www.the4AT.com). He also has developed neuropsychological research tools including the Observational Scale of Level of Arousal (OSLA), and the DelApp, a smartphone-based objective test of inattention in delirium. Alasdair is active in delirium education, advocacy, and clinical implementation. He co-founded the European Delirium Association, co-chaired the Scottish Intercollegiate Guidelines Group (SIGN) national delirium guidelines committee, and is current Chair of the Scottish Government Hip Fracture Audit. Twitter: @a_maclullich.