John Durkin Ph.D sits on the Boards of the International Critical Incident Stress Foundation (ICISF), Crisis Intervention Management, Australasia (CIMA) and is co-director of STAGE-28 International offering training, research and consultancy in crisis intervention and psychological risk assessment. His interest in posttraumatic growth took hold in his early career as a firefighter and was later strengthened by his role in the post-9/11 support effort at New York’s fire and police departments. Convinced that critical incident stress management (CISM) delivered by peers had the potential to prevent a number of mental disorders he sought enhancements that might challenge clinical therapies for effectiveness. Further qualifications and training persuaded Dr Durkin that peers delivering crisis intervention in a person-centered fashion would prove superior to standard treatments for PTSD and facilitate posttraumatic growth. A number of pilot projects have supported this and led to training a team of firefighters in CISM, informed by person-centered theory. When Dr Durkin was called to lead the crisis response for the Metropolitan Police Service following London’s 2017 terrorist attacks and Grenfell Tower fire, the same team of firefighters came in support. Over 80 police officers were seen and no report of PTSD or depression had been received three years later. Growth in police officers and firefighters has been widely reported and awaits empirical confirmation in future projects. The legal demands of occupational safety and health were met during this period leading to the design of a psychological risk assessment for use in the emergency, medical and military services.