New Study: Excited Delirium, Injury, and Use of Force

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A new study led by Simon Baldwin1 examined over 10,700 use of force cases and found a significant risk of adverse outcomes in cases involving excited delirium syndrome (ExDS).2

Researchers assumed that an encounter with someone exhibiting probable ExDS might result in adverse outcomes, including greater levels of force and increased risk of injury to the subject and officer. This latest study was designed to clarify how often these encounters result in multiple use-of-force attempts, ineffective use of force, injuries to subjects, and injuries to officers.

Probable Excited Delirium

Researchers recognized excited delirium as “a state of extreme mental and physiological excitement, characterized by extreme agitation, hyperthermia, hostility, exceptional strength and endurance without apparent fatigue.”3

In 2009, the American College of Emergency Physicians Excited Delirium Task Force identified ten common features of excited delirium.4 In this present study, Baldwin and fellow researchers revised an agency’s post-incident use of force report to capture the presence of these ten features when force encounters involved people perceived to be in emotional crisis.

An encounter was characterized as involving “probable excited delirium” when at least six of the ten potential features of excited delirium were present. These ten features include:

  • pain tolerance
  • constant/near constant activity
  • unresponsive to police presence
  • superhuman strength
  • rapid breathing
  • lack of fatigue
  • naked/inappropriately clothed
  • profuse sweating
  • tactile hyperthermia
  • and glass attraction/destruction.

Summarized Results

After studying five years’ worth of data, researchers observed that force was applied on 10,718 subjects, of which 3,322 were believed to be in an emotional crisis. Of these 3,322 subjects, 197 presented enough features to conclude they were experiencing probable ExDS.

In cases involving probable ExDS (six or more features of ExD), researchers observed that almost half of the encounters involved more than one use of force intervention.

Even after controlling for other risk factors (i.e., perceived drug and alcohol use, violent behavior, a ground struggle, and perceived weapons), researchers reported: “the odds that more force was applied to probable cases of ExDS increased by a factor of almost four.”

Researchers also noted a nearly 400% increase in the odds that a use of force intervention would be ineffective in cases involving probable ExDS. By comparison, subjects perceived to be under the influence of drugs increased the odds that a use of force would be ineffective by only 44%.

When controlling for other risk factors, researchers actually observed a 28% decrease in the odds of suspect injury during encounters involving probable ExDS. However, the odds that an officer would be injured increased by 57%. It should be noted that when other risk factors (i.e., perceived drug and alcohol use, violent behavior, a ground struggle, and perceived weapons) were not controlled for, probable ExDS increased the odds of officer injury by almost two and half times.

Moving Forward

Lead researcher Simon Baldwin is a Ph.D. candidate in psychology at Canada’s Carleton University and a researcher with the Royal Canadian Mounted Police. He is a graduate of the Advanced Force Science Specialist course and was joined in this study by two Force Science instructors, Dr. Christine Hall and Mr. Chris Lawrence.

I spoke with Baldwin, who reiterated, “Our research continues to show that intervention options are less effective against people experiencing excited delirium. Unfortunately, this may mean more force will be necessary to overcome resistance, and with more force, there is an increased risk of officer and suspect injury.”

Baldwin continued, “Excited delirium encounters can be dangerous medical emergencies that simultaneously place officers, subjects, and communities at risk. It’s recommended that officers who intervene in cases involving probable excited delirium respond with containment and quick, coordinated, multiple-officer restraint techniques that minimize the suspect’s exertion and maximize their ability to breathe. This approach will also help expedite monitoring of vitals and handing off to EMS for immediate medical intervention. Our previous studies have identified the risks associated with excited delirium. In our next study will address police intervention options that are most effective and least injurious in these encounters.”

The complete report, titled “Adverse outcomes in non-fatal use of force encounters involving excited delirium syndrome” can be accessed by clicking the button below.

Please note the above link will direct you to a third-party website that charges an access fee to view the full research article. The Force Science Institute itself is not charging for this paper and does not receive payment, in part or in full, for copies of the publication.

Readers can also find details of Baldwin’s earlier excited delirium research at Force Science News, New Study: Perils & Protections In Dealing With Excited Delirium.

Editor’s Note:

Excited delirium symptoms warn of a potentially fatal medical condition. Officers properly trained to recognize ExD are more likely to practice arrest and restraint techniques that mitigate the risk to the patient. They are more likely to have planned, trained, and initiated a cooperative emergency response with dispatchers, emergency medical services, and hospital emergency staff.

The FSI de-escalation courses reinforce that communication and tactics must be integrated to reduce the risk of injuries and get timely medical attention to the person in crisis.

  1. Ph.D. candidate, Carleton University, Ottawa, Ontario, Canada, and graduate of the Advanced Force Science Specialist course. []
  2. The National Association of Medical Examiners formally recognized Excited Delirium Syndrome in 2004. The American College of Emergency Physicians formally recognized ExDS in 2009. The American Medical Association recognizes that ExD “is a widely accepted entity in forensic pathology.” While it is frequently argued that ExD is not found in the International Classification of Diseases (ICD-10) and is therefore not relied on by the American Medical Association or the American Psychiatric Association, the various conditions that can cause ExD are listed in the ICD-10. []
  3. Simon Baldwin, Brittany Blaskovits, Christine Hall, Chris Lawrence & Craig Bennell (2021): Adverse outcomes in non-fatal use of force encounters involving excited delirium syndrome, Police Practice and Research, DOI: 10.1080/15614263.2021.1958682 citing Morrison, A., & Sadler, D. (2001). Death of a psychiatric patient during physical restraint. Excited delirium – A case report. Medicine, Science, and the Law, 41(1), 46–50. https://doi.org/10.1177/002580240104100109 []
  4. American College of Emergency Physicians Excited Delirium Task Force. (2009). White paper report on excited delirium syndrome. []
1 Response
  1. Jesse Buchholtz

    Capture and Control Techniques in the P.E.P. program taught by (Ret.) Lt. John Domingo, with Huntington Beach PD, in California is what our agency adopted here in Colorado. His program was adopted with CA POST and being taught throughout California. We have been using that for 4 1/2 years to great effect on ALL resistive type people, to include the ones spoken about in this study. Proper communication, teamwork, leg control (along with arm controls), hobble restraints on legs, medical monitoring, immediate medical care, has all been the successful protocol. Tracking him down is what I recommend. It would be great if this was pushed worldwide.

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