In 1985, researchers Charles Wetli and David Fishbain coined the term “excited delirium” to describe subjects who exhibited resistive, violent and agitated behavior during police encounters. By the early 2000s, the term was commonly cited as a cause or contributor of death for individuals who died in police custody after exhibiting extreme agitation and aggressive resistance. Though “excited delirium” was never identified as a diagnosis by the American Psychiatric Association (APA) or the American Medical Association (AMA), it was officially recognized in 2009 by the American College of Emergency Physicians (ACEP) in a white paper report. The term was sometimes shortened to “EXD” (for “excited delirium”) or “ExDs” (for “excited delirium syndrome”).

Since then, the use of the term has been reevaluated and eventually disavowed by the AMA and APA, as well as the National Association of Medical Examiners (NAME) and the American College of Medical Toxicology (ACMT) – in part because of evidence that the term may have been disproportionately applied to Black men. Eventually, the American College of Emergency Physicians also disavowed the term, “unendorsing” its 2009 paper in October 2023. That same month, the state of California enacted legislation banning the term in police reports, court testimony, autopsy reports and death certificates.

Lexipol removed the term “excited delirium” from policy guidance in 2022 and recommends that all public safety agencies carefully review with local counsel whether to use the term in reports, policies and procedures. For more information about the move away from “excited delirium,” please see the article, “Excited Delirium: Understanding the Evolution Away from a Controversial Term.”

Here are four things you should know about the condition formerly known as “excited delirium” and how to respond to subjects exhibiting signs of extreme physical and mental stress.

1. Subjects in crisis often pose a threat to themselves and others.

Regardless of terms and terminology, law enforcement officers will still encounter highly agitated subjects in the course of their everyday work. The causes of violent, out-of-control behavior are many and varied: drug/alcohol use and mental illness are the most obvious, but potential triggers also include infections, head injuries, reactions to medication, major surgery, aging and diabetes.

In a 2018 study of the condition (published before the term was disavowed by medical organizations), the authors noted that police encounters with highly agitated individuals:

1. Frequently (89% of the time) involved a struggle between the subject and arresting officer(s) that went to the ground.
2. Frequently (82% of the time) involved the subject assaulting the officer(s) and/or threatening bodily harm or death.
3. Often, common use of force techniques such as pain compliance, TASER device deployment, manual force and OC spray were found to be ineffective.

One of the major reasons the term “excited delirium” has been so universally deprecated by medical groups is because it has been so frequently used to describe altercations that resulted in the death of the subject. When responding to a scene involving a violently agitated subject, extreme care must be taken to do everything possible to de-escalate the situation in an effort to reduce the risk of harm to subjects, officers and others.

2. Regardless of what it’s called, it’s still a medical emergency.

When called to a scene where a person is extremely agitated, the reasons behind the behavior aren’t as important as how law enforcement personnel respond. When reasonable, it’s best to do the following:

1. Immediately request backup. When responding and dealing with highly agitated persons, having adequate personnel on scene prior to any approach may reduce the risk of injury to both the officers and the subject. Note: While a multiple-officer response may seem like the best tactic to limit the duration of the struggle, it’s extremely important for officers not to “pile on.” Should restraint tactics be necessary to safely secure the subject, the subject’s condition should be promptly checked and continuously monitored.
2. Call for medical help. Request EMS response immediately (before the subject is even approached) so you have emergency medical personnel on hand to respond and assist once the subject is safely secured.
3. Request specialized help. When possible, get help from members of your local crisis intervention team (CIT), from community crisis mental health personnel, or from someone else with specialized training in managing subjects in crisis.
4. Give the subject space. If possible, put some distance between officers and the subject to reduce the risk of injury or violence and give additional time for backup to arrive. Keeping a barrier between you and the subject or using cover and concealment may help.
5. Try to calm the subject. If safe and feasible, turn off lights and sirens, lower the volume on radios, and adopt a quiet, non-threatening stance when speaking to the subject. Ask the subject’s name and try to establish a dialogue.
6. Seek more information. When possible, gather information on the subject from family members and/or friends to help establish rapport and increase your understanding of what the person is currently going through.

This list was adapted from IACP Law Enforcement Policy Center guidance regarding “Responding to Persons Experiencing a Mental Health Crisis.” We recommend reviewing this invaluable resource for additional information.

3. Rely on emergency medical personnel.

If you’re able to get EMS on scene in time, solicit and follow their advice regarding the timing, manner and duration of any methods you use to restrain the person.

If subduing highly agitated subjects is necessary, officers should (when practical and safe to do so) concentrate on restraint without using large muscle groups, which minimizes the buildup of lactic acid, decreasing the risk of potential cardiac arrest. Because a prolonged struggle increases the chance of sudden death, officers should focus on effecting the quickest possible restraint. If a subject wants to be seated upright and isn’t fighting, it’s best to allow that to happen. Regardless, it’s critical to monitor the subject’s breathing continuously throughout the encounter.

4. Describe the encounter accurately.

In radio traffic, public statements and written reports regarding the incident, follow best practices regarding law enforcement efforts to respond to incidents involving agitated subjects:

1. Describe, don’t diagnose. Police officers are not mental or medical health professionals; leave the diagnoses to someone else. Instead, describe what you see and hear as plainly and accurately as you can, using dispassionate language and avoiding the term “excited delirium.”
2. Indicate attempted interventions. Knowing the dangers of interacting with highly agitated subjects also means taking all possible care to avoid injuries or death. Be sure to describe the precautions you took during the encounter — such as calling for backup and/or EMS support, attempts to de-escalate the situation, or specific restraint methods — when you document it after the fact.
3. Be sensitive. Remember that the causes of the kind of violent agitation being described here are many and varied. The person you’re dealing with is likely not in control of their actions. Keep that in mind as you talk and write about the situation after the fact.

When responding to a scene involving a violently agitated subject, extreme care must be taken to do everything possible to de-escalate the situation in an effort to reduce the risk of harm to subjects, officers and others.

It’s possible that new terms or descriptions may eventually be coined to refer to subjects who until recently would have been described as experiencing “excited delirium.” Until that happens, these best practices should help ensure that individuals in crisis exhibiting violent or agitated behaviors are taken into custody or otherwise receive the services that they need with minimal risk to law enforcement officers, members of the public and the subjects themselves.

Note: This article, originally published January 6, 2020, has been significantly revised to bring it in line with current thinking and policy and law regarding highly agitated subjects and the term “excited delirium.”