Risk factors for drug-induced deaths (FAQ drug-induced deaths in Europe)
Introduction
There are identified circumstances and risk factors associated with drug-induced deaths, and this section provides an overview of the evidence in this area. Special focus is given to overdose with suicidal intent among women, and to the needs of people in prison or being released from prison.
This page is part of the Frequently asked questions (FAQ): drug-induced deaths in Europe.
What are the common situations that increase the risk of overdose?
There are individual, situational and organisational risk factors for overdoses and they can be modified to reduce fatal outcomes (Frischer et al., 2012).
Individual and situational factors include the type of drugs used, the route of administration, the use of several drugs together, age and decreased tolerance to opioids and other drugs.
The type of substance used, the route of administration and the health of the user all have an impact on the risk of overdose. Most overdose deaths are linked to the use of opioids, primarily the injection of heroin or synthetic opioids, while polydrug use is also very common, including the combination of heroin or other opioids with other central nervous system depressants, such as alcohol or benzodiazepines, which bears particularly high risks. Using, and especially injecting drugs alone, is also a risk factor for overdose death.
A number of environmental factors increase the risk of drug overdose death, including, in the case of people who use opioids, disruption of treatment provision or discontinuity of treatment and care. In certain situations, for example, following detoxification or discharge from drug-free treatment, the person’s tolerance to opioids is greatly reduced and, as a result, they are at a particularly high risk of overdosing if they resume use. For these same reasons, inadequate continuity of care between prison and community life has also been identified as an important environmental risk factor (Degenhardt et al., 2014; WHO Regional Office Europe, 2010; Zlodre and Fazel, 2012).
A cohort study carried out in England (United Kingdom) identified differences in the risk of fatal opioid poisoning that were dependent on the type of treatment received: opioid users who received only psychological support appeared to be at a greater risk than those who received opioid agonist treatment (Pierce et al., 2016). This adds to the body of evidence that supports enrolling and retaining high-risk opioid users in opioid agonist treatment (see the EUDA Best practice portal), providing access to harm reduction interventions and ensuring continuity of care between prisons and the community and at other transition points (see also the publication Prison and drugs in Europe: current and future challenges (EMCDDA, 2021a)).
Is there a sex difference in deliberate self-poisonings?
Determining the intention of a person who has died from a drug overdose can be difficult. Many overdose deaths are reported as accidental, and others have an undetermined intent. The availability of such information varies between countries. This information is derived from the codes used to certify the cause of death in the national statistics offices or general mortality registries. Some countries do not report data from this source (see Where do the data come from?) and, thus, do not report information on the intentionality of drug-induced deaths. However, in some countries, information is available on intention, and a relatively high proportion of reported overdose deaths (1 in 8 overall) were classified as intentional in 2022 and 2023 (that is, with a suicidal intent). In all EU Member States, except Malta, and in Norway, the most recent available data show that the proportion of overdose deaths with a suicidal intent was higher among women. In the Netherlands and Sweden in 2022-2023, more than a third of the reported overdose deaths among women were classified as having a suicidal intent. In the same period, in Denmark, Finland, Hungary, Poland and Slovenia, a suicidal intent was recorded for one fifth or more of the overdose deaths among females.
In addition, the prevalence of psychiatric comorbidity among people who use drugs is higher among women compared with males. Moreover, among people using drugs women are more likely to have experienced gender-based violence and use drugs as a form of self-medication for past trauma (Haro et al., 2023; Jones et al., 2018; Torrens et al., 2011).
Recent reviews also find that the rate ratios of suicide, or rates compared with those in the general population of the same sex and similar age, are typically higher among people in prison (Fazel et al., 2017) and that suicide can be one of the leading causes of death in prison (Désesquelles et al., 2018). The wide range of risk factors across clinical and custody-related domains underscores the need for a comprehensive, prison-wide approach towards preventing self-harm in prison (Favril et al., 2020).
These findings indicate the need for interventions that target deliberate self-harm and suicidal intent among people who use drugs, and especially to recognise the disproportional risk that females may experience in this context, as well as persons in prison.
More information on this topic can be found in the drug-related deaths section of the 2025 European Drug Report.
Resources and references
Consult the methodological information and list of references on the Frequently asked questions (FAQ): drug-induced deaths in Europe main page.