Simon is a psychiatrist and epidemiologist. He started his psychiatry training in 1984, joining King’s College School of Medicine (as it was) in 1991, and has been at the Institute of Psychiatry, Psychology and Neurosciences, King’s College London, ever since.

His is the first ever Regius Chair at KCL, and the first Regius Chair of Psychiatry in the UK. He is Co-Director of the King’s Centre for Military Health Research, established by him in 1996. Since 2013 he has been Director of the PHE NIHR Health Protection Unit for Emergency Response and Preparedness - very active during the COVID-19 crisis.

He is a Fellow of the Royal College of Physicians, Royal College of Psychiatrists, Academy of Medical Sciences, and Royal Society. He is a Past President of the Royal College of Psychiatrists and Royal Society of Medicine. In 2017-19 he led the Independent Review of the Mental Health Act, paving the way for new legislation in 2022.

Simon’s main areas of research lie in unexplained symptoms/syndromes, military health, epidemiology, clinical trials and how people react to adversity. To date, Simon has written 850 professional publications.