Updated medical guidance reject 'excited delirium' to prevent misuse in police custody cases

Updated medical guidance on excited delirium, the controversial term accused of covering up deaths in police custody, including that of George Floyd, is being brought forward before its scheduled date of October 2025, reports The BMJ today.

The move comes as attitudes towards the use of the term appear to be changing, explains journalist Chris Stokel-Walker. For instance, last month Colorado joined California in banning police, medical staff and coroners from using the term, and the UK Independent Office of Police Conduct (IOPC) removed the phrase from its incident forms.

The phrase "excited delirium" was first coined by two doctors working in Miami in the 1980s, but subsequent analyses have never found a reliable medical basis for its use in the medical lexicon.

Yet it and a related term more common in the UK, "acute behavioral disturbance" (ABD), have been mentioned as a cause of death or contributing factor in 44 cases of UK police restraint since 2005, according to an investigation published in March 2024 by the charity Inquest, the Royal College of Psychiatrists and the Observer. 

An earlier study published in July 2023 found that mentions of ABD in mental health records in one London NHS trust increased year-on-year between 2006 and 2021.

James MacCabe, professor of epidemiology and therapeutics at King's College London, believes that the use of both terms is misguided, while Catherine Polling, NIHR clinical lecturer in general psychiatry, also at King's College London, says: "It's not traditionally a term that we use, and it's not in any of our diagnostic manuals."

The guidance, produced by the Faculty of Forensic & Legal Medicine (FFLM), part of the Royal College of Physicians, is used to inform police forces' handling of suspects in custody. 

In 2019, the guidance linked excited delirium and ABD together, discussing how the two overlapped with one another. But an updated version in 2022 shied away from using excited delirium and included additional warnings about using specific forms of restraint and medicine that could result in harm or death to those it was being enacted upon. 

Controversy over the terms are well-warranted, argues MacCabe. "In the case of George Floyd, it's quite clear what is happening: it's being used as a way of explaining the fact that people have died when they've been in police custody or when they've been restrained, and it's a way of deflecting attention away from the restraint techniques that might have been used." 

There is also another reason why it's such a controversial diagnosis, says MacCabe: it seems to be predominantly applied to black people.

The same July 2023 analysis that tracked ABD mentions in the London NHS trust found that black people were more than twice as likely to have ABD referenced in mental health assessments than white people, while a US analysis of 166 reported deaths in police custody between 2010 and 2020 attributed to excited delirium found that black people were 43.3% of the reported deaths. 

A separate study shows that excited delirium is mostly cited as a cause of death in people who have previously been restrained. 

The IOPC said in a statement: "We have decided to stop using the term 'excited delirium' as we recognize that it is language that is outdated and potentially offensive. We have removed it from IOPC forms that police forces use to make referrals to us and will not use the term as an option for categorizing our investigations." 

While unable to share a draft of the new FFLM guidance, Margaret Stark, one of the authors, can confirm that it updates references to include the latest knowledge, and removes references to non-clinical terms such as "disproportionate superhuman strength."

Stark is happy to see the back of excited delirium but thinks losing the term 'acute behavioral disturbance' would be a mistake. She points to the importance of having a label for when people feel severe anxiety in police custody, because feeling that anxiety can lead to changes in the body that become a medical emergency. 

Experts agree it's time to find a better term, but what should replace excited delirium?

Andrew Stolbach, associate professor of emergency medicine at Johns Hopkins University, says that not having a way to define the issues he encounters with patients does them a disservice, though he dislikes "excited delirium." He says he'd prefer to describe the symptoms in front of him, rather than assume a diagnosis without further tests.

He believes it also serves another, more noble, purpose. "Whenever there's a term that's historically been associated with racism, it's important to be sensitive to that," he says. "We need to recognize the weight that carries. And that's just even more reason to move on."