News Release

New study: Opioids kill, especially if you're alone

A new study from Aarhus University has investigated 327 deaths in Jutland that occurred after an overdose of methadone or morphine

Peer-Reviewed Publication

Aarhus University

The researcher


Although data on illicit drugs involved in deaths are reported to the Danish Health and Medicines Authority every year, very little is known about any common circumstances when people die from opioids. A study from the Department of Forensic Medicine has changed this, and Clinical Associate Professor Charlotte Uggerhøj Andersen hopes the study will lead to better counselling, especially for young people. Photo: Simon Byrial Fischel

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Credit: Photo: Simon Byrial Fischel - Aarhus University

They slow down breathing. First, you lose consciousness, then your heart stops beating.

The opioids methadone and morphine are the most common cause of fatal drug poisoning in Denmark. A study from the Department of Forensic Medicine at Aarhus University has investigated the circumstances behind morphine-, heroin-, and methadone-related deaths in the period 2013 to 2020 in the four police districts covered by the department - North Jutland, East Jutland, Central and West Jutland and Southeast Jutland.

One of the conclusions is that it is more dangerous to use opioids when you are alone.

The study shows that 64 per cent of the 327 people who died were alone at the time of death, and the majority seemed to be unaffected by drugs when they were last seen alive.

"It’s important to recognise that sleep is a precursor to opioid poisoning. People don't usually die immediately after an overdose, it can take hours before oxygen deficiency causes in a sleep-like state and organs shut down," says Charlotte Uggerhøj Andersen, a clinical associate professor at the Department of Forensic Medicine at Aarhus University. She and her colleagues are behind the study, which has just been published in the scientific journal Forensic Science International.

"If you have the right knowledge, you’ll be ready to react. It's about waking people up, and if you can't do that, call the emergency services. The risk of a fatal outcome is much higher if there’s no one to intervene," she says.

Blood analyses from deceased

The study describes where opioid poisonings occur. It looks at whether the person was alone at the time of death, and whether sleep and snoring were observed before death. It also provides an analysis of toxicological findings in the deceased's blood. During an autopsy, forensic pathologists perform a toxicological analysis of the blood of the deceased and screen it for more than 700 drugs and metabolites.

A forensic autopsy is mandatory for deaths related to illegal narcotics. Autopsies are performed at the request of the police, and the most common cause of death in these cases is opioid poisoning.

"There’s a particular risk of poisoning from opioid use because of the relatively narrow gap between an intoxicating dose to give a high, and a fatal overdose," says Charlotte Uggerhøj Andersen.

An autopsy report also includes a description of death written by a forensic pathologist based on information from the police investigation. The description includes statements from the deceased's general practitioner and witnesses, and there is a description of conditions at the place of death, if available. By scrutinising these reports, researchers have been able to study various determining factors related to fatal opioid poisonings, which cannot be collected from health data or cause-of-death registries.

Among other things, the study shows that people aged 15-34 are more likely to die from opioid poisoning while others are present at the address than people over the age of 44.

"In many cases, other people had seen the deceased asleep after taking the drug. It’s important to speak up if you've taken opioids. Young people need to know that they should keep an eye on each other, and it’s important that you don't just leave anyone who is sleeping if you suspect that they may have taken drugs - you have to wake them up," urges Charlotte Uggerhøj Andersen.

The vast majority of people in the study over the age of 44 died alone.

The study also shows that, in fatal cases, the opioids were almost always taken in combination with other drugs, such as benzodiazepines, which are used to treat anxiety and sleep problems.

"It’s important to communicate the risks of cocktail drug usage to all age groups, especially the use of sedatives or alcohol with opioids, as this can amplify their effects," says the researcher.

"Our study emphasises the need for harm-reduction initiatives in both urban and rural areas. It’s important to communicate the risks and warning signs of opioid use, and to recognise sleep as a precursor to fatal poisoning, especially among younger age groups," says Charlotte Uggerhøj Andersen.

Still a lack of knowledge

The study was conducted in collaboration with Antidote Danmark, an NGO of doctors, nurses and volunteers who provide information on how to recognise overdoses and stop opioid overdoses with an antidote nasal spray.

"There is generally very little knowledge about opioid abuse in Denmark," says Michael Lodberg Olsen, the general manager of Antidote Danmark. The organisation has a wide range of contacts with drug communities, addiction centres, shelters, music venues, schools and youth networks.

"It’s particularly important to disseminate the results of the study to young people who use opioids or are in environments where this happens. It's crucial that they know the signs of poisoning. Because you can't save yourself from an overdose - someone else has to intervene," he says.

"The message from the authorities is: Say no to drugs. We stress: Don't do drugs alone. Now there's even more weight behind our words," he says.


Facts - numbers from the study

  • The study looked at autopsy reports on 327 people who died after poisoning with the opioids methadone and morphine in the period 2013-2020.
  • The deceased came from one of four police districts: North Jutland, East Jutland, Central and West Jutland and Southeast Jutland.
  • 92 of the 327 deceased were between 15 and 34 years old.
  • 202 of the deceased (62%) died or were found dead in their own home.
  • 68 people (21%) died or were found dead in another private home - most often on a bed or sofa.
  • 210 (64%) were alone at the time of death, and the majority appeared unaffected by drugs when they were last seen alive.
  • In 97 cases (30%), other people were at the same address when death occurred.


The research results - more information

  • The study is a cross-sectional study of fatal poisonings caused by methadone or heroin/morphine.
  • It is a collaboration between Peter Andreas Andersen, Asser Hedegaard Thomsen, Freja Drost Andersen, Jørgen Bo Hasselstrøm, Jakob Ross Jornil and Charlotte Uggerhøj Andersen from the Department of Forensic Medicine, Aarhus University, and Jakob Hartvig Thomsen and Michael Lodberg Olesen from Antidote Danmark.
  • Read more in the scientific article "Exploring death scenes and circumstances in fatal opioid poisonings: Insights for preventive strategies using forensic autopsy cases in Western Denmark ":



Clinical Associate Professor Charlotte Uggerhøj Andersen
Aarhus University, Department of Forensic Medicine and Aarhus University Hospital, Clinical Pharmacology
Telephone: +45 60 12 84 30

Forensic Chemist, PhD, Jakob Ross Jornil
Aarhus University, Department of Forensic Medicine
Telephone: + 86 16 83 57


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