Dr Gallagher is a psychiatrist in East London Foundation Trust. He is undertaking dual training in general adult and older adult psychiatry; with accreditation in acute hospital liaison psychiatry and a special interest in substance misuse. He also holds a role as clinical lecturer at Queen Mary University of London on the Physician Associate course and is active in medical education within the medical school and more widely - having held a position as Fellow in Medical Education in North East London Foundation Trust. He graduated from medicine at University College London and returned to undertake a master's degree in Mental Health Sciences Research during the course of his training.

Recently he has contributed to research on the impact of COVID within Older Adult psychiatric wards and has published research on novel psychoactive substances use amongst psychiatric patients. During his recent older adult psychiatry placement, he worked closely with the Tower Hamlets Integrated Care team, providing psychiatric input for frail individuals in nursing homes, alongside geriatrician colleagues from the Royal London Hospital.