Born in Epsom and brought up in Surbiton, Surrey, he created the Hessle-based Agencia company after a medical career that had begun as a clinical psychologist in a new department at Broadgate Hospital, Beverley.
By his late 20s he was the head of department there, while at the same time carrying out private counselling. Eventually he moved into consultancy roles at Humberside University and then became director and company secretary of a market research company.
Agencia’s client roster, from 1997, included the Ministry of Justice, Foreign and Commonwealth Office, the Department of Health and numerous probation trusts, clinical commissioning groups and other government bodies. When the Hull City Health Care Partnership was set up, Dr Gibson was its consultant.
He remained chairman of Agencia until his death but reduced his involvement following his diagnosis with a brain tumour in 2016.
He and his wife, Elaine, whom he married in 1974, had two daughters and two sons, and three grandchildren.