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“Excited Delirium” – Often Cited as Cause of Death in Fatal Police Encounters – Is Scientifically Meaningless: PHR Report

New Physicians for Human Rights (PHR) report traces the history, impacts, and pseudoscience behind “excited delirium,” highlighting the need for clinicians and law enforcement to end use of the “baseless” diagnosis rooted in racism

A new investigation published today by Physicians for Human Rights (PHR) finds that “excited delirium” – often cited as a cause of death in fatal encounters with law enforcement – is not a valid medical diagnosis and should no longer be used by clinicians, attorneys, or law enforcement.  

“‘Excited Delirium’ and Deaths in Police Custody: The Deadly Impact of a Baseless Diagnosis” is the first study to date on “excited delirium” to combine a medical literature review, deposition transcripts, news archives, and extensive interviews with medical, legal, and policing experts, as well as with family members of people whose deaths in police custody were attributed to “excited delirium.” The landmark report traces the history of “excited delirium,” its baseless scientific underpinnings and roots in anti-Black racism, and the profound harms caused by the continued use of the pseudoscientific phrase.  

Some of the co-authors also penned a Comment article in the medical journal The Lancet to accompany the report: “End the Use of ‘Excited Delirium’ as a Cause of Death in Police Custody.” 

The PHR report concludes that “excited delirium” is not a valid, independent medical or psychiatric diagnosis. The term is scientifically meaningless because of the lack of consensus or rigorous evidentiary basis. Researchers found that “excited delirium” does not have a clear or consistent definition, established etiology, or known underlying pathophysiology. Instead, “excited delirium” has become a catch-all, misleading explanation for many deaths occurring in the context of law enforcement restraint, often coinciding with substance use or mental illness, and disproportionately used to explain the deaths of Black men in police encounters. 

“‘Excited delirium’ is pseudoscience that all too often provides cover for fatal police tactics,” said Altaf Saadi, MD, MSc, general academic neurologist at Massachusetts General Hospital, instructor of neurology at Harvard Medical School, and report co-author. “The scientific foundations underpinning the diagnosis of ‘excited delirium’ have been grossly misrepresented and distorted, often fueled by conflicts of interest involving TASER/Axon Enterprise and law enforcement agencies. Based on our rigorous analysis, we call on the two remaining medical associations whose members still use the term regularly – the American College of Emergency Physicians (ACEP) and the National Association of Medical Examiners (NAME) – to affirmatively disavow the concept of ‘excited delirium’ as a cause of death and no longer offer a veil of medical legitimacy to this baseless and dangerous term.”  


PHR report co-authors and experts, including the Quinto-Collins family, discussed the report findings and recommendations at an online briefing held on March 2, 2022.

PHR’s report reconstructs the history of the term “excited delirium” through an in-depth review of the medical literature, news archives, and deposition transcripts of expert witnesses in wrongful death cases. Researchers evaluated current views and applications of the term through interviews with 20 medical and legal experts on deaths in law enforcement custody, as well as with six experts on severe mental illness and substance use. PHR also interviewed members of two families (those of Angelo Quinto and Daniel Prude) whose loved ones’ deaths were attributed to “excited delirium” rather than to the conduct of law enforcement, providing firsthand accounts of the extreme harms of the term’s continued use. 

The report draws on expertise from a range of medical specializations. Co-authors, interviewees, and reviewers together included forensic pathologists, emergency physicians, internal medicine physicians, a psychiatrist, a neurologist, and a cardiologist. Multiple attorneys helped contextualize the findings – as researchers, interviewees, and reviewers – but had no influence over the medical findings or conclusions. 

The report also includes new details on the origins of “excited delirium,” including shocking quotes from the term’s originator that have been overlooked by members of the medical community for more than three decades.

Archival materials reveal how “excited delirium” cannot be disentangled from its racist and unscientific origins. For example, Dr. Charles Wetli, who first coined the term with Dr. David Fishbain in case reports on cocaine intoxication in 1981, soon after extended his theory to explain how more than 12 Black women in Miami died after consuming small amounts of cocaine. “For some reason the male of the species becomes psychotic and the female of the species dies in relation to sex,” he told the Miami News. The women, along with at least seven others who were found dead in the same time period, were later found to have been killed by a serial killer, not stricken by a female version of “excited delirium.” Even after the murdered women’s true cause of death was found not to be from cocaine, Dr. Wetli continued to push a corresponding theory of Black male death from cocaine-related delirium, without any scientific basis: “Seventy percent of people dying of coke-induced delirium are black males, even though most users are white. Why? It may be genetic.” 

While this racialized and gendered theory of “excited delirium” should have been promptly discredited, a small group of researchers and consultants – many working on behalf of TASER International (now Axon Enterprise, a U.S. company that produces technology products and weapons) – promulgated the broader use of the term by populating the medical literature with articles about “excited delirium.” However, PHR’s analysis finds that the body of research supporting “excited delirium” is small and of poor quality, with homogenous citations riddled with conflicts of interest.  

In 2007, TASER/Axon purchased many copies of a book entitled Excited Delirium Syndrome, written by one of its defense experts, Dr. Vincent Di Maio, and his wife Theresa Di Maio, that built on Dr. Wetli’s construct of “excited delirium” by describing an “excited delirium syndrome.” TASER/Axon, whose “Taser” line of electroshock weapons were found in one study to be connected to almost half of deaths attributed to “excited delirium,” distributed the book for free and disseminated related materials at forensic pathology conferences – helping to ensure widespread familiarity with the term among the small community of U.S. forensic pathologists and medical examiners. Seven years later, during a deposition, Dr. Di Maio acknowledged that he and his wife had “come up with” the term “excited delirium syndrome.” 

“‘Excited delirium’ cannot be separated from its racist and misogynistic origins,” said Joanna Naples-Mitchell, JD, PHR U.S. researcher and report co-author. “Today, the concept of ‘excited delirium’ endangers Black people and other people of color, given that it exploits racist tropes of ‘superhuman strength’ and ‘impervious[ness] to pain’ and perpetuates discrimination in law enforcement settings. Disproportionally used to explain the in-custody deaths of Black men, ‘excited delirium’ is a clear manifestation of systemic racism in both the justice system and in medicine. Its continued use in death investigations and in courts contributes to impunity for police killings. Clinicians should reject this harmful and unscientific concept immediately and urge their peers to do the same.” 

“The prevalence of excited delirium as a diagnosis was made clear to us when we first met our lawyers and were told that Angelo’s death would be blamed on it,” said Cassandra Quinto-Collins, mother of Angelo Quinto, whose December 2020 death was attributed to “excited delirium” and whose story is highlighted in the report. “Eight months later, at the coroner’s inquest, that prediction came to fruition. From the disregard for witness testimony to the denial of medical evidence, we’re experiencing firsthand the harm of this pseudoscientific diagnosis.” 

“Excited delirium” continues to be used by coroners and forensic pathologists to explain deaths in law enforcement custody in the United States. An Austin-American Statesman investigation into each non-shooting death of a person in police custody in Texas from 2005 to 2017 found that more than one in six deaths (of 289 total) were attributed to “excited delirium.” A January 2020 Florida Today report found that of 85 deaths attributed to “excited delirium” by Florida medical examiners since 2010, at least 62 percent involved the use of force by law enforcement. Of at least 166 reported deaths in police custody from possible “excited delirium” from 2010 to 2020 nationally, Black people made up 43.3 percent, and Black and Latinx people together made up at least 56 percent, according to a December 2021 article in the Virginia Law Review. Use of TASER/Axon’s products was connected to 47 percent of cases. Overall figures of deaths in law enforcement custody have been shown to be drastically underreported by U.S. officials. 

“This landmark report confirms what civil rights lawyers and their clients have known for years – ‘excited delirium’ is a baseless diagnosis aimed at protecting police who kill people during restraint, and denying the victims and their families justice,” said report co-author Julia Sherwin, JD, longtime civil rights lawyer and partner at Haddad & Sherwin LLP in Oakland, California. “All too often, police use strongarm tactics on people in a mental or behavioral health crisis, with disastrous results. We need a national system requiring that these medical and mental health emergencies be treated as health matters and not law enforcement matters, which will save lives and reduce officer injuries.”    

“There is no rigorous scientific research that examines prevalence of death for people with ‘excited delirium’ who are not physically restrained – indeed, this spurious diagnosis is almost exclusively brought up in the context of law enforcement interactions,” said Michele Heisler, MD, MPA, medical director at Physicians for Human Rights, professor of internal medicine and of public health at the University of Michigan, and report co-author. “People who present with symptoms often attributed to ‘excited delirium’ – such as agitation, confusion, fear, hyperactivity, acute psychosis, sweats, noncompliance with directions – should be recognized as having an underlying diagnosis and treated accordingly, be it a mental health, substance use disorder, or other form of crisis. We must transform emergency response for people in crisis in this country, not only to change the ways law enforcement personnel are trained but also to provide the necessary social and mental health care and support for people before they reach a crisis point. We need to ensure that health professionals – not law enforcement – are the primary responders and decision-makers in mental health and substance use crises.” 

The report offers detailed recommendations to the American College of Emergency Physicians and National Association of Medical Examiners (the two medical associations whose members most often promote “excited delirium” as a diagnosis and cause of death), as well as to other medical associations and clinicians, state and local governments, the Biden administration, Congress, and United Nations human rights mechanisms.  

Physicians for Human Rights (PHR) is a New York-based advocacy organization that uses science and medicine to prevent mass atrocities and severe human rights violations. Learn more here.

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