 Benzodiazepines are one of the most commonly prescribed psychoactive medicines worldwide. They depress the central nervous system by enhancing the actions of a neurotransmitter known as GABA, which has a calming effect on many of the functions of the brain. Benzodiazepines have a high therapeutic value in the treatment of anxiety, stress and insomnia, but they should only be used for a short time because dependence and tolerance can develop within weeks. In general, benzodiazepines and any other psychiatric medication has its clear indications to be used. Outside those indications, people start having drugs by their own. It's like any other drug of abuse. Problem-opioid users are particularly vulnerable to misuse of benzodiazepine. They often use them in combination with heroin, methadone and alcohol. In Europe, 11% of clients entering treatment for opioid problems report benzodiazepine as a secondary drug, with some country reporting level up to 50%. Prevalence levels can be even higher among patients in opioid substitution treatment. For some drug users, it's actually for the reward, potentiating effect usually of other drugs. Other drug users use benzodiazepines because they are dependent on them and so they self-medicate for withdrawal symptoms usually. And then there's another group who self-medicate for mental health problems. Traditionally, benzodiazepines are prescribed, but other sources come into play, especially the illicit market. And the illicit market is made up of theft from pharmacies, pill machines, producing very poor quality illicit benzodiazepines. In this moment, to be honest, benzodiazepines are acquired on the street for low prices. It's always been like that. The doctor didn't accept me, I wanted to try again. Benzodiazepine are recognized as generally safe, but in combination with other substances such as opioids, they increase respiratory depression and the risk of overdose. This is reflected in the high prevalence of benzodiazepine in the post-mortem examination of fatal overdose cases. The simultaneous use of opioids and benzodiazepine is also linked with other consequences. They are negative for the health of the user, for the drug treatment outcome, and for the social functioning. It has also a huge impact on emergencies and non-fatal intoxications. The EuroDen project collected data on acute drug intoxications, presenting to emergency rooms. What we found was that just over 26% of presentations involved prescription drugs, and benzodiazepines were the most common group. We've looked at the heroin-benzodiazepine co-intoxications and found that they were associated with a longer length of stay in hospital and a greater proportion of patients who are admitted to critical care, suggesting the potential for greater toxicity associated with the combination. Our understanding of the risk and benefits of using benzodiazepines, including the interactions with other substances such as opioids, has increased over the last decade. This knowledge should be properly disseminated among practitioners and patients. Prescribing practices and clinical guidance can play an important role in the management of benzodiazepine use among high-risk opioid users. But it's equally important to prevent the diversion of these medicines into the illicit market, including the illicit sale on the internet.