Since the American Civil War, it has been known that the soldiers and others exposed to the war and disasters of critical-type incidents have experienced among other symptoms, restlessness irritability, excessive fatigue, sleep disturbances, anxiety, startle reactions, depression, moodiness, muscle tremors, difficulties concentrating, nightmares, vomiting, diarrhea, and suspiciousness. Even Freud was impressed with the quantity and intensity of the stress response symptoms experienced by the World War I veterans. He found that those who had been exposed to traumatic events repeatedly experienced mental images of those frightening scenes even when they tried to forget them. Researchers have concluded that just seeing gory sights or hearing distressing sounds is enough to trigger stress responses in people. (excerpt from When Disaster Strikes: The Critical Incident Stress Debriefing Process, Jeffrey T. Mitchell, Ph.D.; JEMS Magazine. Jan. 83).

It is believed that emergency services workers deal with a stress response similar to that seen in war.

There are many methods to deal with a stress response syndrome. One such method is know as Critical Incident Stress Debriefing (CISD). A CISD is an organized approach to the management of stress responses in emergency services. It entails either an individual or group meeting between the rescuer and a caring individual(s). The CISD model utilizes a team of 50% mental health professionals and 50% peer support debriefers. Together the team uses a 7-phase process to discuss, or debrief, the critical incident. The goal of the CISD is to protect and support emergency services personnel and to minimize the development of abnormal stress response syndromes with may cause lost time and effectiveness at the work and problems within the family.

Jeffrey T. Mitchell, MS, was a full-time faculty member of the Emergency Health Services Program of the University of Maryland Baltimore County. He is the senior author of the book, Emergency Response to Crisis, and holds Masters degrees in Counseling Psychology and Clinical Psychology. He completed work on his Ph.D., with his dissertation to be on paramedic stress. Mr. Mitchell was a certified EMT-A Instructor and had served as an EMS coordinator and a firefighter/paramedic. He specialized in crisis intervention and critical incident stress debriefings and has facilitated many CISDs. Some of the early critical incidents that Jeffrey Mitchell utilized his CISD model were: 1978 Pacific Southwest Airlines crash in San Diego, 1980 Air Florida crash, and the Kansas City Hyatt Regency Hotel disaster in 1981.