In 1998, he moved to UCL Queen Square Institute of Neurology to pursue research on mind-brain-body interactions, working between the Functional Imaging Laboratory (Wellcome Department of Imaging Neuroscience) and the clinical Autonomic Unit at the National Hospital for Neurology and Neurosurgery.
He completed his general training as a neuropsychiatrist in 2003 and gained a Wellcome Trust Senior Fellowship in Clinical Science in 2004.
Clinically, Critchley trained as an neuropsychiatrist and helped establish a service in 2006, for adult neurodevelopmental conditions (including Autism, ADHD and developmental tics) at the Sussex Partnership NHS Foundation Trust, where he works as a psychiatrist.
[4] His most cited article described interoceptive representations in the human brain [5][6] Critchley has been involved in the Academic Faculty of the Royal College of Psychiatrists which he chaired from 2019 to 2024, and he has previously served as a member of the Council of the American Psychosomatic Society.
In 2015, Critchley became a Fellow of the Royal College of Psychiatrists and, in 2017, he received the Paul D MacLean Award from the American Psychosomatic Society.