Background: The present paper describes the results of a rating study performed by a group of European Union (EU) drug experts using the multi-criteria decision analysis model for evaluating drug harms. Methods: Forty drug experts from throughout the EU scored 20 drugs on 16 harm criteria. The expert group also assessed criteria weights that would apply, on average, across the EU. Weighted averages of the scores provided a single, overall weighted harm score (range: 0–100) for each drug. Results: Alcohol, heroin and crack emerged as the most harmful drugs (overall weighted harm score 72, 55 and 50, respectively). The remaining drugs had an overall weighted harm score of 38 or less, making them much less harmful than alcohol. The overall weighted harm scores of the EU experts correlated well with those previously given by the UK panel. Conclusion: The outcome of this study shows that the previous national rankings based on the relative harms of different drugs are endorsed throughout the EU. The results indicates that EU and national drug policy measures should focus on drugs with the highest overall harm, including alcohol and tobacco, whereas drugs such as cannabis and ecstasy should be given lower priority including a lower legal classification.

In the the past two decades the medical use of prescription opioids (POs), in particular oxycodone, increased up to 14-fold in the U.S. and Canada. The high consumption of these pain relievers also led to non-medical use and abuse of these substances which in turn resulted in a dramatic increase in the number of PO related fatalities and opioid dependent subjects. In the U.S. POs became the second most prevalent type of abused drug (4.5 million abusers; 1.7% of the population) after marijuana (8 million abusers) with currently 1.9 million (0.7% of the population) people dependent on opioid pain relievers. Pain relief was the leading motive for non-medical use in about 40% of the cases, but about half of non-medical PO users reported non-pain relief motives only, like to get high or to relax. Since 2011, there is a decline in the use and misuse of POs and reduction in painkiller overdose deaths in the U.S. probably due to the introduction of a variety of restrictive regulations. In Europe, the medical use of POs is increasing as well, but at a much slower rate than in the U.S. Moreover, in Europe non-medical use of POs and fatal PO incidents are (still) rare. The paper highlights and discusses the differences between Europe versus U.S. and Canada in an attempt to assess the risk of a PO abuse and overdose epidemic in Europe. It is concluded that the risk in Europe seems to be rather limited but vigilance is needed.

Cannabis use is associated with an increased risk of psychosis in vulnerable individuals. Cannabis containing high levels of the partial cannabinoid receptor subtype 1 (CB₁) agonist tetrahydrocannabinol (THC) is associated with the induction of psychosis in susceptible subjects and with the development of schizophrenia, whereas the use of cannabis variants with relatively high levels of cannabidiol (CBD) is associated with fewer psychotic experiences. Synthetic cannabinoid receptor agonists (SCRAs) are full agonists and often more potent than THC. Moreover, in contrast to natural cannabis, SCRAs preparations contain no CBD so that these drugs may have a higher psychosis-inducing potential than cannabis. This paper reviews the general toxicity profile and the adverse effects of SCRAs with special emphasis on their psychosis-inducing risk. The review shows that, compared with the use of natural cannabis, the use of SCRAs may cause more frequent and more severe unwanted negative effects, especially in younger, inexperienced users. Psychosis and psychosis-like conditions seem to occur relatively often following the use of SCRAs, presumably due to their high potency and the absence of CBD in the preparations. Studies on the relative risk of SCRAs compared with natural cannabis to induce or evoke psychosis are urgently needed.

Background: Given the ongoing opioid crisis in the United States (US), we investigated the opioid situation in Europe. The aims of the study are to provide an overview of trends in prescription opioid (PO) use and opioid-related adversities between 2010 and 2018 for different opioids in 19 European countries and to present a comparison with similar data from the US. Methods: A multisource database study with national data from 19 European countries evaluating trends between 2010 and 2018 in (a) PO consumption, (b) high-risk (HR) opioid users, (c) opioid-related hospital admissions, (d) opioid-related overdose deaths, (e) opioid use disorder treatment entries, and (f) patients in opioid substitution therapy (OST). Within and between-country comparisons and comparisons with data from the US were made. Results: There was considerable variation between European countries. Most countries showed increased PO consumption with the largest increase and the highest consumption in the United Kingdom (UK) compared to the rest of Europe and the US in 2018 (UK: 58,088 defined daily doses for statistical purposes/1000 population/day). In 2018, Scotland had the highest rates (per 100,000 population) of HR opioid users (16·2), opioid-related hospital admissions (118), opioid-related deaths (22·7), opioid use disorder treatment admissions (190), and OST patients (555) of all included European countries. These rates were similar or even higher than those in the US in 2018. Other countries with high rates of opioid-related adversities were Northern Ireland (synthetic and “other” opioids), Ireland (heroin and methadone), and England (all opioids). All other countries had no or little increase in opioid-related adversities. Conclusions: Apart from the British Isles and especially Scotland, there is no indication of an opioid crisis comparable to that in the US in the 19 European countries that were part of this study. More research is needed to identify drivers and develop interventions to stop the emerging opioid crisis in the UK and Ireland.

In the U.S., an opioid overdose crisis has emerged, attributable to over-prescription of opioid analgesics, driven by aggressive marketing by pharmaceutical companies, followed by surging heroin overdose deaths, and more recently, by the high mortality rates predominately because of illicitly manufactured fentanyl and analogs of fentanyl. In Europe, the use of prescription opioids for pain management has also increased in the last 2 decades, although it is debatable as to whether this could lead to a similar opioid overdose crisis. To address this issue, recent trends in opioid prescription rates, prevalence rates of fatal and nonfatal incidents, and addiction care treatment were used as proxies of opioid-related harm. The current overview, comparing opioid use and its negative consequences in Germany, France, the U.K., and the Netherlands, using the same indicators as in the U.S., demonstrates that there is no evidence of a current or emerging opioid crisis in these European countries. Scotland, however, is an alarming exception, with high rates of opioid-related harms. Considering that the use of prescription opioids has been declining rather than increasing in Europe, an opioid crisis is not anticipated there yet. Authorities should, however, remain vigilant.