Digby worked in the NHS for nearly 40 years as a general psychiatrist and later a consultant psychotherapist. He began the first clinic in the world for the assessment of autistic adults in 1980. He is an existential psychotherapist and a group analyst. He is an Emeritus Professor of Psychiatry in the University of Sheffield; a Visiting Professor of Psychology at Middlesex University; and Deputy Principal of the New School of Psychotherapy in London, where He is course leader for the MA in Diversity Studies.