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Critical Incident Stress Debriefing (CISD) 

Jeffrey T. Mitchell, Ph.D. 

Diplomate 

American Academy of Experts in Traumatic Stress and 

Clinical Professor of Emergency Health Services 

University of Maryland 

Introduction and Definition of CISD: 

The term “debriefing” is widely used and means many different things. In fact, there are many different 

types of “debriefings” in use in the world today. Most forms of debriefing do not equate to the “Critical 

Incident Stress Debriefing.” One needs to be very careful and know exactly what type of debriefing they 

are discussing. Precision in the use of terminology is extremely important. Inaccurate definitions lead to 

faulty practice and flawed research. 

Critical Incident Stress Debriefing (CISD) is a specific, 7-phase, small group, supportive crisis 

intervention process. It is just one of the many crisis intervention techniques which are included under 

the umbrella of a Critical Incident Stress Management (CISM) program. The CISD process does not 

constitute any form of psychotherapy and it should never be utilized as a substitute for psychotherapy. It 

is simply a supportive, crisis-focused discussion of a traumatic event (which is frequently called a “critical 

incident”). The Critical Incident Stress Debriefing was developed exclusively for small, homogeneous 

groups who have encountered a powerful traumatic event. It aims at reduction of distress and a 

restoration of group cohesion and unit performance. 

A Critical Incident Stress Debriefing can best be described as a psycho-educational small group process. 

In other words, it is a structured group story-telling process combined with practical information to 

normalize group member reactions to a critical incident and facilitate their recovery. A CISD is only used 

in the aftermath of a significant traumatic event that has generated strong reactions in the personnel from 

a particular homogeneous group. The selection of a CISD as a crisis intervention tool means that a 

traumatic event has occurred and the group members’ usual coping methods have been overwhelmed 

and the personnel are exhibiting signs of considerable distress, impairment or dysfunction. 
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The Facilitators 

The CISD is led by a specially trained team of 2 to 4 people depending on the size of the group. The 

typical formula is one team member for every 5 to 7 group participants. A minimal team is two people, 

even with the smallest of groups. One of the team members is a mental health professional and the 

others are “peer support personnel.” A unique feature of CISD is that Critical Incident Stress Management 

trained peer support personnel (firefighters, paramedics, police officers, military personnel, etc.) work with 

a mental health professional when providing a CISD to personnel from law enforcement, fire service, 

emergency medical, military, medical, aviation and other specialized professions. A peer is someone 

from the same profession or who shares a similar background as the group members. Police officers, for 

instance, who have been trained in Critical Incident Stress Management techniques, are selected to work 

with police officers who have been through the traumatic event. Fire service personnel with CISM 

background are chosen to work with firefighters and CISM trained emergency medical or military 

personnel will be placed on teams running a Critical Incident Stress Debriefing with their respective 

groups and so on. 

Essential Concepts in CISD 

A Critical Incident Stress Debriefing is small group “psychological first aid.” The primary emphasis in a 

Critical Incident Stress Debriefing is to inform and empower a homogeneous group after a threatening or 

overwhelming traumatic situation. A CISD attempts to enhance resistance to stress reactions, build 

resiliency or the ability to “bounce back” from a traumatic experience, and facilitate both a recovery from 

traumatic stress and a return to normal, healthy functions. 

The Critical Incident Stress Debriefing is not a stand-alone process and it is only employed within a 

package of crisis intervention procedures under the Critical Incident Stress Management umbrella. A 

CISD should be linked and blended with numerous crisis support services including, but not limited to, 

pre-incident education, individual crisis intervention, family support services, follow-up services, referrals 

for professional care, if necessary, and post incident education programs. The best effects of a CISD, 

which are enhanced group cohesion and unit performance, are always achieved when the CISD is part of 

a broader crisis support system. 

Historical Perspective and Theoretical Foundations 

Critical Incident Stress Debriefing was developed by Jeffrey T. Mitchell, Ph.D. in 1974 for use with small 

homogeneous groups of paramedics, firefighters and law enforcement officers who were distressed by an 

exposure to some particularly gruesome event. It is firmly rooted in the crisis intervention and group 

theory and practices of such notables as Thomas Salmon, Eric Lindemann, Gerald Caplan, Howard 
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Parad, Lillian Rapoport, Norman Faberow, Calvin Frederick and Irvin Yalom. The first article on CISD 

appeared in the Journal of Emergency Medical Services in 1983. 

Over time, the use of Critical Incident Stress Debriefing spread to other groups outside of the emergency 

services professions. The military services, airlines, and railroads find the process helpful. This is 

particularly so when it is combined and linked to other crisis intervention processes. Businesses, 

industries, hospitals, schools, churches and community groups eventually adopted the Critical Incident 

Stress Debriefing model as an integral part of their overall staff crisis support programs. 

Objectives 

A Critical Incident Stress Debriefing has three main objectives. They are: 1) the mitigation of the impact 

of a traumatic incident, 2) the facilitation of the normal recovery processes and a restoration of adaptive 

functions in psychologically healthy people who are distressed by an unusually disturbing event. 3) A 

CISD functions as a screening opportunity to identify group members who might benefit from additional 

support services or a referral for professional care. 

Required Conditions for the Application of the CISD Process 

The Critical Incident Stress Debriefing requires the following conditions: 

1) The small group (about 20 people) must be homogeneous, not heterogeneous. 2) The group members 

must not be currently involved in the situation. Their involvement is either complete or the situation has 

moved past the most acute stages. 3) Group members should have had about the same level of 

exposure to the experience. 4) The group should be psychologically ready and not so fatigued or 

distraught that they cannot participate in the discussion. 

An assumption is made here that a properly trained crisis response team is prepared to provide the CISD. 

The Critical Incident Stress Debriefing Process 

Timing 

The Critical Incident Stress Debriefing is often not the first intervention to follow a critical incident. A brief 

group informational process may have taken place and distressed individuals may have been supported 

with one-on-one interventions. Typically, 24 to 72 hours after the incident the small, homogeneous group 

gathers for the CISD. Intervention delays may occur in disasters. Personnel may be too involved in the 

event to hold the CISD earlier. They may not be psychologically ready to accept help until things settle 

down a bit after they finish work at the disaster scene. In fact, it is not uncommon in disasters that the 

CISD is not provided for several weeks and sometimes longer after the disaster ends. Depending on the 
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circumstances, a CISD may take between 1 and 3 hours to complete. The exact time will depend on the 

number of people attending and the intensity of the traumatic event. 

Phases in the Critical Incident Stress Debriefing 

A CISD is a structured process that includes the cognitive and affective domains of human experience. 

The phases are arranged in a specific order to facilitate the transition of the group from the cognitive 

domain to the affective domain and back to the cognitive again. Although mostly a psycho-educational 

process, emotional content can arise at any time in the CISD. Team members must be well trained and 

ready to help the group manage some of the emotional content if it should arise in the group. 

Phase 1 – Introduction 

In this phase, the team members introduce themselves and describe the process. They present 

guidelines for the conduct of the CISD and they motivate the participants to engage actively in the 

process. Participation in the discussion is voluntary and the team keeps the information discussed in the 

session confidential. A carefully presented introduction sets the tone of the session, anticipates problem 

areas and encourages active participation from the group members. 

Phase 2 – Facts

Only extremely brief overviews of the facts are requested. Excessive detail is discouraged. This phase 

helps the participants to begin talking. It is easier to speak of what happened before they describe how 

the event impacted them. The fact phase, however, is not the essence of the CISD. More important parts 

are yet to come. But giving the group members an opportunity to contribute a small amount to the 

discussion is enormously important in lowering anxiety and letting the group know that they have control 

of the discussion. The usual question used to start the fact phase is “Can you give our team a brief 

overview or ‘thumbnail sketch’ of what happened in the situation from you view point? We are going to go 

around the room and give everybody an opportunity to speak if they wish. If you do not wish to say 

anything just remain silent or wave us off and we will go onto the next person.” 

Phase 3 – Thoughts 

The thought phase is a transition from the cognitive domain toward the affective domain. It is easier to 

speak of what one’s thoughts than to focus immediately on the most painful aspects of the event. The 

typical question addressed in this phase is “What was your first thought or your most prominent thought 

once you realized you were thinking? Again we will go around the room to give everybody a chance to 

speak if they wish. If you do not wish to contribute something, you may remain silent. This will be the last 

time we go around the group.” 
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Phase 4 – Reactions

The reaction phase is the heart of a Critical Incident Stress Debriefing. It focuses on the impact on the 

participants. Anger, frustration, sadness, loss, confusion, and other emotions may emerge. The trigger 

question is “What is the very worst thing about this event for you personally?” The support team listens 

carefully and gently encourages group members to add something if they wish. When the group runs out 

of issues or concerns that they wish to express the team moves the discussion into the next transition 

phase, the symptoms phase, which will lead the group from the affective domain toward the cognitive 

domain. 

Phase 5 – Symptoms

Team members ask, “How has this tragic experience shown up in your life?” or “What cognitive, physical, 

emotional, or behavioral symptoms have you been dealing with since this event?” The team members 

listen carefully for common symptoms associated with exposure to traumatic events. The CISM team will 

use the signs and symptoms of distress presented by the participants as a kicking off point for the 

teaching phase. 

Phase 6 – Teaching

The team conducting the Critical Incident Stress Debriefing normalizes the symptoms brought up by 

participants. They provide explanations of the participants’ reactions and provide stress management 

information. Other pertinent topics may be addressed during the teaching phase as required. For 

instance, if the CISD was conducted because of a suicide of a colleague, the topic of suicide should be 

covered in the teaching phase. 

Phase 7 – Re-entry

The participants may ask questions or make final statements. The CISD team summarizes what has been 

discussed in the CISD. Final explanations, information, action directives, guidance, and thoughts are 

presented to the group. Handouts maybe distributed. 

Follow-up 

The Critical Incident Stress Debriefing is usually followed by refreshments to facilitate the beginning of 

follow-up services. The refreshments help to “anchor” the group while team members make contact with 

each of the participants. One-on-one sessions are frequent after the CISD ends. 
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Other follow-up services include telephone calls, visits to work sites and contacts with family members of 

the participants if that is requested. At times, advice to supervisors may be indicated. Between one and 

three follow-up contacts is usually sufficient to finalize the intervention. In a few cases, referrals for 

professional care may be necessary. 

Research: 

The research on CISD is quite positive if two conditions are present. The conditions are: 

1. Personnel have been properly trained in CISM. 

2. Providers are adhering to well published and internationally accepted standards of CISM practice. 

Note: Without exception, every negative outcome study on CISD to date has not used trained 

personnel to provide the service and they have violated the core standards of practice in the CISM 

field. For example, they have used the CISD for individuals instead of homogeneous groups. The 

Cochrane Review (Wessely, Rose and Bisson, 1998) summarizes the negative outcome studies on 

CISD. In that review, 100% of the studies were performed on individuals. When a group process 

designed for homogeneous groups is used on individuals, it changes the inherent nature of the 

process itself and also what is being measured. In addition, the negative outcome studies applied a 

group process model to individuals for whom the CISD process was never intended. The Cochrane 

Review studies covered dog bite victims (9% of the studies), auto accident victims (45% of the 

studies), burn victims (9% of the studies), relatives of actual victims in an emergency department (9% 

of the studies), sexual assault victims and women who had a miscarriage, a cesarean section, post 

partum depression and other difficult pregnancy situations (28% of the Cochrane Review studies). 

The CISD small group process was not designed to manage any of these types of cases. It was 

developed for use with small, homogeneous groups such as fire fighters, police officers, military and 

emergency services personnel. CISD should be used for staff, not primary victims. 

The paragraphs below present an overview of some of the positive outcome studies. There are many 

more beyond what can be addressed here. 

Bohl (1991) assessed the use of CISD with police officers. Police officers who received a CISD within 24 

hours of a critical incident (N=40) were compared to officers without CISD (31). Those with CISD were 

found to be less depressed, less angry and had less stress symptoms at three months than their nondebriefed colleagues. 

Bohl (1995) studied the effectiveness of CISD with 30 firefighters who received CISD compared with 35 

who did not. At three months, anxiety symptoms were lower in the CISD group than in the non-CISD 

group. 

In a sample of 288 emergency, welfare, and hospital workers, 96% of emergency personnel and 77% of 

welfare and hospital employees who worked on traumatic events stated that they had experienced 

symptom reduction which was attributed partly to attendance at a CISD (Robinson & Mitchell, 1993). 
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After a mass shooting in which 23 people were killed and 32 were wounded, emergency medical 

personnel were offered CISD within 24 hours. A total of 36 respondents were involved in this longitudinal 

assessment of the effectiveness of CISD interventions. Recovery from the trauma appeared to be most 

strongly associated with participation in the CISD process. In repeated measures anxiety, depression, 

and traumatic stress symptoms were significantly lower for those who participated in CISD than for those 

who did not (Jenkins, 1996). 

After a hurricane, Chemtob, Tomas, Law, and Cremniter (1997) did pre- and post-test comparisons of 41 

crisis workers in a controlled time-lagged design. The intervention was a CISD and a stress 

management education session. The intervention reduced Posttraumatic stress symptoms in both 

groups. 

In naturalistic quasi-experimental study emergency personnel working the civil disturbance in Los 

Angeles in 1992 were either given CISD or not depending on the choice of command staff. They had 

worked at the same events. Those who received CISD scored significantly lower on the Frederick 

Reaction Index at three months after intervention compared to those who did not receive it (Wee, Mills, & 

Koehler, 1999). 

In 1994 over 900 people drowned in the sinking of the ferry, Estonia. Nurmi (1999) contrasted three 

groups of emergency personnel who received CISD with one group of emergency nurses who did not 

receive CISD. Symptoms of posttraumatic stress disorder were lower in each of the CISD groups than 

the non-CISD category. 

When CISD is combined with other interventions within a CISM program the results are even stronger. In 

a study on traumatized bank employees (Leeman-Conley, 1990), a year with no assistance for 

employees was compared with a year in which a CISM program was used. Employees fared better with 

the CISM program. Sick leave in the year in which the CISM program was utilized was 60% lower. 

Additionally, workers compensation was reduced by 68%. 

Western Management Consultants (1996) did a cost benefit analysis on a CISM program for nurses. The 

study involved 236 nurses (41% of the work force). Sick time utilization, turnover and disability claims 

dropped dramatically after the program was put in place. The cost benefit analysis showed $7.09 (700% 

benefit) was saved for every dollar spent on building the CISM program. 

A recent evaluation of group crisis interventions was undertaken by Boscarino, Adams and Figley (2005). 

People working in New York City at the time of the World Trade Center attacks on September 11, 2001 

who were offered crisis intervention services by their employers were compared to other workers whose 
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employers did not offer any form of organized crisis intervention services. Assessments conducted at 

one and again at two years after the traumatic events of September 11, indicate that those who received 

group Critical Incident Stress Management services demonstrated benefits across a spectrum of 

outcomes in comparison to workers without crisis intervention services. Lower levels of alcohol 

dependency, anxiety, PTSD symptoms, and depression were among the outcomes that indicated a 

marked difference between those receiving CISM services and who were not offered such services. 

The reader is also directed to the reviews already performed on CISM (Hiley-Young & Gerrity, 1994; 

Dyregrov, 1997, 1998; Flannery, 2001; Everly et al., 2001, Mitchell, 2003a, 2004b). The following 

paragraphs summarize the research issues in the CISM field. 

With the exception of randomized controlled studies by Deahl et al. (2000) and Campfield and Hills (2001) 

studies supportive of CISM and the small group CISD are all quasi experimental designs. Randomized 

controlled trials are certainly encouraged, however, the opportunity to conduct them under disaster field 

conditions may be extremely difficult or impossible (Jones & Wessely, 2003). 

Further Readings and References 

American Psychiatric Association (1964). First aid for psychological reactions in disasters. Washington, 

DC: American Psychiatric Association. 

Bohl, N. (1991). The effectiveness of brief psychological interventions in police officers after critical 

incidents. In J.T. Reese and J. Horn, and C. Dunning (Eds.) Critical Incidents in Policing, Revised (pp.31-

38). Washington, DC: Department of Justice. 

Bohl, N. (1995). Measuring the effectiveness of CISD. Fire Engineering, 125-126. 

Boscarino, J.A., Adams, R.E. & Figley, C.R. (2005). A Prospective Cohort Study of the Effectiveness of 

Employer-Sponsored Crisis Interventions after a Major Disaster. International Journal of Emergency 

Mental Health, 7(1), 31-44 

Campfield, K. & Hills, A. (2001). Effect of timing of critical Incident Stress Debriefing (CISD) on 

posttraumatic symptoms. Journal of Traumatic Stress, 14, 327-340. 

Caplan, G. (1964). Principles of preventive psychiatry. New York: Basic Books. 

Chemtob, C., Tomas, S., Law, W., and Cremniter, D. (1997). Post disaster psychosocial intervention. 

American Journal of Psychiatry, 134, 415-417 

Deahl, M., Srinivasan, M., Jones, N., Thomas, J., Neblett, C., & Jolly, A. (2000). Preventing psychological 

trauma in soldiers. The role of operational stress training and psychological debriefing. British Journal of 

Medical Psychology, 73, 77-85. 

Dyregrov, A. (1997). The process in critical incident stress debriefings. Journal of Traumatic Stress, 10, 

589-605 
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Everly, G.S., Jr., Flannery, R. B., Jr., Eyler, V. & Mitchell, J.T. (2001). Sufficiency analysis of an integrated 

multi-component approach to crisis intervention: Critical Incident Stress Management. Advances in MindBody Medicine, 17, 174-183. 

Farberow, N. L., & Frederick, C. J. (1978). Disaster relief workers burnout syndrome. Field Manual for 

Human Service Workers in Major Disasters. Washington, DC: US Government Printing Office. 

Flannery, R.B. (1998). The Assaulted Staff Action Program: Coping with the Psychological Aftermath of 

Violence. Ellicott City, MD: Chevron Publishing. 

Flannery, R.B., Jr. (2001). Assaulted Staff Action Program (ASAP): Ten years of empirical support for 

Critical Incident Stress Management (CISM). International Journal of Emergency Mental Health, 3, 5-10. 

Flannery, R.B. (2005). Assaulted Staff Action Program (ASAP): Fifteen years of Empirical Findings. Paper 

presented at the 8th World Congress on Stress Trauma and Coping: Crisis Intervention: Best Practices in 

Prevention, Preparedness and Response. Baltimore, Maryland, USA February 16-20, 

Frederick, C. J. (1977). Crisis intervention and emergency mental health. In Johnson, W.R. (ed), Health in 

Action. New York: Holt, Rinehart and Winston. 

Hiley-Young, B. & Gerrity, E.T. (1994).Critical Incident Stress Debriefing (CISD): Value and limitations in 

disaster response. NCP Clinical Quarterly, 4, 17-19. 

Jenkins, S.R. (1996). Social support and debriefing efficacy among emergency medical workers after a 

mass shooting incident. Journal of Social Behavior and Personality, 11, 447-492. 

Jones, E. and Wessely, S. (2003). “Forward Psychiatry” in the military: it’s origins and Effectiveness. 

Journal of Traumatic Stress, 14 (4), 411-419. 

Lindemann, E. (1944). Symptomatology and management of acute grief. American Journal of Psychiatry, 

101, 141-148. 

Mitchell, J. T. (1983). When disaster strikes ... The critical incident stress debriefing process. Journal of 

Emergency Medical Services, 13(11), 49 – 52. 

Mitchell, J.T. (1986). Teaming up against critical incident stress. Chief Fire Executive, 1(1), 24; 36; 84.

Mitchell, J.T. (2003a). Crisis Intervention and Critical Incident Stress Management: Aresearch summary. 

Ellicott City, MD: International Critical Incident Stress Foundation. 

Mitchell, J.T. (2003b). Major Misconceptions in Crisis Intervention. International Journal of Emergency 

Mental Health, 5 (4), 185-197 

Mitchell, J.T. (2004a). Characteristics of Successful Early Intervention Programs. International Journal of 

Emergency Mental Health, 6 (4), 175-184. 

Mitchell, J.T. (2004b). Critical Incident Stress Management (CISM): A defense of the field . Ellicott City, 

MD: International Critical Incident Stress Foundation. 

Mitchell, J.T. & Bray, G. (1990). Emergency Services Stress: Guidelines for preserving the health and 

careers of emergency service personnel. Englewood Cliffs, NJ: Prentice Hall. 

Mitchell, J.T. & Everly, G.S., Jr., (2001). Critical Incident Stress Debriefing: An operations manual for 

CISD, Defusing and other group crisis intervention services, Third Edition. Ellicott City, MD: Chevron. 
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Mitchell, J.T. & Everly, G.S., Jr. (2001). Critical Incident Stress Management: Basic Group Crisis

Interventions. Ellicott City, MD: International Critical Incident Stress Foundation.

Nurmi, L. (1999). The sinking of the Estonia: The effects of Critical Incident Stress Debriefing on

Rescuers. International Journal of Emergency Mental Health, 1, 23-32. 

Parad, L., & Parad, H. (1968). A study of crisis oriented planned short –term treatment: Part II. Social 

Casework, 49, 418-426. 

Robinson, R.C. & Mitchell, J.T. (1993) Evaluation of psychological debriefings. Journal of Traumatic 

Stress, 6(3), 367-382. 

Salmon, T. S. (1919). War neuroses and their lesson. New York Medical Journal, 108, 993-994. 

Wee, D.F., Mills, D.M. & Koelher, G. (1999). The effects of Critical Incident Stress Debriefing on 

emergency medical services personnel following the Los Angeles civil disturbance. International Journal 

of Emergency Mental Health, 1, 33-38. 

Wessely, S., Rose, S., & Bisson, J. (1998). A systematic review of brief psychological interventions

(debriefing) for the treatment of immediate trauma related symptoms and the prevention of post traumatic 

stress disorder (Cochrane Review). Cochrane Library, Issue 3, Oxford, UK: Update Software.

Western Management Consultants. (1996). The Medical Services Branch CISM Evaluation Report.

Vancouver, B.C.: Author. 

Yalom, I. (1970) The theory and practice of group psychotherapy. New York: Basic Books.