Dr Brown died on 19 September 2004. He had a distinguished career in psychiatry and obtained a distinction in the DPM in 1969 and an MD from Leeds in 1970. Dennis had been a research assistant at the Academic Department of Psychiatry at the Middlesex Hospital for 3 years under Dennis Hill where his research was on psychological aspects of skin disorders. He decided to train as a psychoanalyst and qualified as an Associate Member of the British Psycho-Analytic Society in 1972; in 1971 he became a Founder Member of the Royal College of Psychiatrists and FRCPsych in 1978. In 1982 he became FRCP (Edin).

Dennis joined the Cassel Hospital as a medical assistant in 1966 at a time when it was a stimulating training ground for psychoanalytic psychotherapists under the direction of Tom Main. This experience of therapeutic community influenced him in turning towards group analysis, the school of S. H. Foulkes, famous through his work at Northfield Hospital during the Second World War. Group analysis became his principal field of work in both hospital and private practice and he contributed many important publications in this area. He was a much loved and admired teacher and training analyst at the Institute of Group Analysis.

After his work at the Cassel Hospital, Dennis held Consultant Psychotherapist posts at St Mary's and St George's Hospitals, was a recognised teacher, University of London examiner and external examiner for Leeds University Postgraduate Diploma in Psychotherapy. He was President of the Group Analytic Society London from 1983 to 1988 and took a leading role in the new field of transcultural group analysis to which he contributed several papers.

Dennis and Jonathan Pedder, his colleague at St Mary's Hospital, co-authored the very successful Introduction to Psychotherapy, now in its third edition. With his friend and colleague at St George's Hospital, the late Louis Zinkin, he co-edited The Psyche and the Social World, a significant addition to group-analytic literature.

Dennis had a delightful personality: warm, witty, sensitive and cultured. With his wife Dorothy, who had co-authored a cookery book, they created an ambiance of hospitality and good cheer, particularly welcoming to colleagues from abroad.

Dennis struggled valiantly against the spread of cancer. He died peacefully in a hospice. Fortunately a collection of his papers will appear in the near future under the title Resonance and Reciprocity (Routledge).