This controversial condition isn't recognized by many medical professionals.

Over the past two years, at least two unarmed Black men who have died in police custody—Daniel Prude and Elijah McClain—were described as having "excited delirium" before their deaths. Though the condition is not recognized by leading medical associations, a diagnosis of excited delirium is used by police and emergency medicine professionals to restrain and treat those who appear to be in a delirious, out-of-control state. (One of the officers charged in the George Floyd case was concerned that Floyd could be suffering from excited delirium during the arrest that led to his death.)

So what exactly is excited delirium, why is it so controversial, and is there racial bias when it comes to diagnosing it? Here are the facts.

What is excited delirium?

First described in the mid-1800s, excited delirium is characterized by a sequence of events including "delirium with agitation (fear, panic, shouting, violence, and hyperactivity), sudden cessation of struggle, and respiratory arrest," according to a 2011 overview in the West Journal of Emergency Medicine. Death might also be at the end of that sequence, according to the overview.

"It's on the border of psychiatric and neurological syndromes, but it's not a psychiatric diagnosis that's in the DSM-5," Adam Bisaga, MD, a professor of psychiatry at Columbia University Irving Medical Center, tells Health, referring to the Diagnostic and Statistical Manual of Mental Disorders. "We often see it in people who use high doses of stimulants like cocaine or methamphetamines."

The condition is controversial in the medical community because, as Dr. Bisaga says, it's not listed in the DSM-5, nor is it an accepted diagnosis or syndrome by the American Medical Association, the American Psychiatric Association, or the World Health Organization.

What are the signs of excited delirium?

Excited delirium is marked by acute agitation; a person will be in a disoriented state and may become aggressive and hyper. Heart rate and body temperature will increase, and sedation may be necessary so the person doesn't harm themselves or others. "It has some psychiatric components, like people are usually violent, agitated, often paranoid, and confused or disoriented," explains Dr. Bisaga.

Excited delirium is more than just being highly panicked and fearful. "The critical issue here is it's a delirious state of disorientation and confusion as opposed to someone who is violent and agitated or paranoid. They're afraid for their lives, which is somewhat different," says Dr. Bisaga. "With this delirious syndrome, we know something major is happening with the patient. You have high heart rate, your heart might stop pumping, you have overheating, you have rigidity, your muscles break apart, they clog their kidneys. This is a medical emergency."

For this reason, Dr. Bisaga says health professionals should recognize excited delirium as a medical issue that requires urgent care, rather than as a behavioral issue with no need for immediate intervention—which could lead to serious complications or even death.

What causes excited delirium?

"It's thought to be caused by hyperactive dopamine," Mark Pappadakis, DO, a New Jersey-based emergency medicine physician at Capital Health Regional Medical Center in Trenton, tells Health. (Dopamine is a neurotransmitter, a chemical messenger that influences behavior and physical body functions.)

One explanation for an uptick in dopamine levels is drug use, specifically cocaine. "Cocaine targets dopamine in the brain and causes a 'surge,' the same surge you get from doing your favorite hobby or jogging—except this is tenfold, leading the smallest trigger to create an alarming, hyperactive state," says Dr. Pappadakis. Excited delirium is also linked to a history of schizophrenia and bipolar disorder, he adds.

Whatever the exact cause, the sharp increase in dopamine levels can be life-threatening. "Prolonged exposure in this kind of state, or any kind of agitated force, can result in a massive heart attack or heart attack-like phenomenon where the heart gives out and leads to sudden death," he says.

How is excited delirium treated?

First, doctors will attempt to verbally calm the patient. If that doesn't work, they'll typically use physical restraint like wrist and ankle-locking. If the patient is violent and not yet at a hospital, they may be sedated on site by EMS workers, or the sedation could occur in the ER. "Sometimes these people can't really be deescalated safely, and it's pretty obvious when they come in," says Dr. Pappadakis.

The first-line sedative is usually Versed or Ativan—followed by ketamine, if those don't appear to work. (Though the use of ketamine to sedate someone with excited delirium has come under fire since Elijah McClain's 2019 death; he was reportedly given a much higher dose of the drug than he should have for his weight.) "The sedatives move very quickly via injection, and within a few minutes will slow and stop the physical agitation," says Dr. Bisaga. "You have to cool the patient off, so we give them a cooling blanket, preventing the patient from exhausting themselves."

While sedation takes effect and the patient may fall asleep, their heart rate and oxygen levels are monitored, because vital functions could be affected by the delirium and possibly any drugs taken, says Dr. Pappadakis. "When they wake up, we have a conversation them, to see if there was any other drug use—because medically speaking, we need to screen for any other toxic substances or any kind of trauma," he says. "They could have fallen and had a cracked rib that they didn't feel."

How can excited delirium lead to death?

Sudden death is absolutely possible with excited delirium. Approximately two-thirds of people diagnosed with excited delirium die at the scene or during police or paramedic transport to a hospital. Daniel Prude, the Black man who died in police custody in Rochester, New York in March, had excited delirium listed as a contributing factor in his death. "By the time the patient gets to the hospital, the patient often is already dead—because during the course of this delirium you have this massive stimulation of the system," says Dr. Bisaga. "The symptoms by themselves or in combination can lead to acute death. You have to stabilize the patient very quickly or they might die."

Is there racial bias when it comes to diagnosing excited delirium?

According to a systematic review of excited delirium cases by the Society for Academic Emergency Medicine, the condition is diagnosed disproportionately in young black men. “Excited delirium has a long history of being used to absolve law enforcement of responsibility in the death of people, especially people of color,” said Homer Venters, MD, former chief of medicine for New York City’s jails, in an article from The Marshall Project on George Floyd's death.

Most cases of excited delirium, according to the review, are a result of stimulant drug use, and it's more common among psychiatric patients. "People of color are disproportionately affected by psychosis," says Dr. Pappadakis. "That much is known because of socioeconomic pressures [that] place them more at risk than white individuals. When you add cheap drugs, it's not a good mix. It could be a recipe for disaster. Anyone with repeated drug abuse, particularly cocaine and PCP, are the two most at-risk populations. And of course, anyone with a history of schizophrenia and bipolar disorder especially."

Dr. Pappadakis says he "wishes he could say no" to the possibility of racial bias in excited delirium cases. "What might be happening, but I can't verify, is that minorities are more likely to experience a delay in care for this condition." Any delay in care should be investigated, along with the disproportionate rates of diagnosis.

To get our top stories delivered to your inbox, sign up for the Healthy Living newsletter