‘Excited Delirium’: When Medical Diagnoses Become Legal Determinants of Causation

Doctors use “diagnostic” labels to describe a condition or constellation of symptoms and signs before determining treatment or rendering a prognosis. Diagnostic criteria generally remain static and serve as a collective reference point for the medical world. Not so for the diagnosis of “excited delirium.”  Not only has the meaning of “excited delirium” morphed over time, but the legal community has conscripted it for non-medical purposes, like defending claims of excessive force by police officers. Recently, the medical community rejected this use and “revoked” the diagnosis. Who benefits?

A Case in Point

Two and a half years ago, a 46-year-old man was arrested for allegedly using a $20.00 counterfeit bill to pay for cigarettes. Struggling and resisting, the suspect was pinned to the ground while the arresting officer thrust his knee on the alleged perpetrator’s neck, pressing for some 9 1/2 minutes. Not surprisingly, the suspect died. His name was George Floyd. The arresting officer was convicted of murder.

His defense? The suspect was suffering from “excited delirium syndrome.”

Police officers are taught this condition manifests as incoherence, violence, paranoia, extraordinary strength, sweating, or abnormal body temperature, or the suspect may suddenly snap - necessitating an aggressive response, including bodily restraints and the use of batons or noxious chemical “pepper” sprays. That these manifestations also arise from fear, stress, or panic, which might “normally” occur from being placed under arrest, is not headlined in training.

“They’re taught that cardiovascular disease, drug abuse, or mental illness can trigger excited delirium.”

Nicole Mackenzie, Minneapolis police officer who trains officers in medical care.

At the time of the trial of Derek Chauvin, the police officer involved in the death of George Floyd, the general medical consensus asserted the diagnosis of “excited delirium” was real. That has now changed.

A Shape-Shifting Diagnosis

The diagnosis was first used in the mid-1800s to suggest treatment for certain psychiatric conditions, including mania and psychotic features of paranoid schizophrenics such as delusions, hallucinations, hyperactivity, disorganized behavior, hyperactive arousal, altered sleep-wake cycles, and elevated core body temperature. As for treatment,

“[I]t would be better to place a patient suffering from such acute degeneration of cerebral function entirely in seclusion [rather] than to aggravate his disorder by … mischievous struggles with attendants.”

Dr. Henry Maudsley, “Physiology and Pathology of the Mind (1887)”

A 1934 review of 28 cases renamed the condition lethal catatonia. Those suffering had a 75% chance of mortality, although, on autopsy, no objective physical evidence of disease was ever found (“other than exhaustion which could well have been brought on by the manifestation of the disease rather than a causal condition.”) Between 1954 and 1975, neuroleptic drugs like Thorazine were used to reduce the incidence of exhaustive mania in institutionalized patients.

Then, in the 1980s, the cocaine epidemic flooded the streets of Miami.

“In the 1980s, the traditional Hippocratic term excited delirium was transplanted from the bedsides of febrile, agitated, and disoriented patients to the streets of Miami. Deaths in custody of young men who were intoxicated with cocaine and who were restrained by the police because of their erratic or violent behaviour were attributed to excited delirium.”

Commensurate with the epidemic came a profusion of “agitated cocaine deaths,” to which the “excited delirium” diagnosis was appended. This described the psychosis, hyperthermia, and sudden respiratory collapse suffered by the abusers. Again, no anatomic cause of death was found on autopsy, although drug overdose, trauma, and underlying cardiac disease were excluded. Could the condition be related to force, excessive or not, used by law enforcement in arresting the addicts?

Over the last forty years, the diagnosis has been appropriated by counsel defending police and manufacturers of conducted energy weapons (CEW), e.g., TASERs. Excited delirium is now used to describe a presentation of “unusual strength, pain tolerance and bizarre behavior,” supposedly justifying excessive force in subduing a suspected perpetrator. Expert witnesses, primarily forensic pathologists, testify about the perilous nature of excited delirium syndrome, even though this diagnostic entity lacks a consistent neuropathological basis and depends entirely on observed behavior. It is no surprise that the term found its way into Derek Chauvin's defense.  

Consensus or Not?

In 2009, the American College of Emergency Physicians validated the diagnosis in a consensus “white paper” for the legal community, law enforcement, and the medical establishment. The White Paper was also used to shape police training.

“It is the consensus of the Task Force that [Excited Delirium Syndrome] is a unique syndrome which may be identified by the presence of a distinctive group of clinical and behavioral characteristics that can be recognized in the pre-mortem state.”

Symptoms associated with the condition were unusual pain tolerance and bizarre behavior, which overlap with features associated with an adrenaline rush precipitated by extreme fear, panic, danger, or another stressful event, e.g., arrest. However, this alternative is not mentioned in the report. The report lists, however,  as alternative causes, genetic susceptibility, chronic stimulant-induced abnormalities of dopamine transporter pathways, and elevation of heat shock proteins in fatal cases.

Pursuant to the Frye case, consensus statements by medical groups may be admitted into evidence. But this October, California legislatively barred the diagnosis and related terms as a cause of death in autopsies, obviating its use in the legal context. The legislation also prohibits police officers from using the term to describe people’s behavior in official reports.

This follows on the heels of the objections of the National Association of Medical Examiners and the American Medical Association, with critics calling the term unscientific and rooted in racism. Shortly after California’s legislation, the American College of Emergency Physicians withdrew its previous approval, saying:

“… the term excited delirium should not be used by members who testify in civil or criminal cases. ‘This means if someone dies while being restrained in custody ... people can’t point to excited delirium as the reason and can’t point to ACEP’s endorsement of the concept to bolster their case,’”

Dr. Brooks Walsh, Connecticut emergency doctor.

Is the diagnosis real?

The research is a definite – maybe.

Some say no. The American Psychiatric Association’s diagnostic handbook doesn’t list the condition, and one study last year concluded it is mostly cited as a cause only when the person who died had been restrained.

“There is no evidence to support ExDS [Excited Delirium Syndrome] as a cause of death in the absence of restraint. These findings are at odds with previously published theories indicating that ExDS-related death is due to an occult pathophysiologic process. When death has occurred in an aggressively restrained individual who fits the profile of either ExDS or AgDS [Agitated Delirium Syndrome], restraint-related asphyxia must be considered a likely cause of the death.”

 The role of restraint in fatal excited delirium Forensic Science, Medicine and Pathology

Some say yes – arguing it is a disorder of dopamine metabolism aggravated by cocaine, methamphetamine, and designer cathinone usage. These advocates claim hyperthermia, an elevated body temperature, is a hallmark of excited delirium and a harbinger of death. Yet, when police officers make the diagnosis, the hyperthermia element is either absent or missed.

However, even the proponents require more than the aberrant behavior, e.g., clouding of consciousness, violent and self-destructive acts, often found in the context of arrests. Those pointing to the dopamine etiology note that fatal cases of this life-threatening febrile condition of EDS were widely recognized by clinicians before modern psychiatric treatments became available.

Who Benefits?

In a 1995 paper, sociologist Phil Brown asked who benefits, or at least avoids trouble, by identifying and using a diagnosis. How do we identify misuse from necessary intervention?

The controversy highlights the misuse of medical diagnoses for legal purposes, especially when objective or pathognomic findings aren’t present. When the disease was first elucidated some 100-plus years ago, most patients died, and police involvement and force were not issues. Relinquishing diagnosis to the legal community or law enforcement, who are not trained in the art, is nothing short of dangerous. Medical diagnoses should remain in the hands of the medical community. But to jettison a diagnosis purely because it was mishandled denies those needing medical help that respite.