In this editorial we discuss the evidence that Europe recently experienced a heroin shortage. The information available suggests that some, but not all, countries experienced a severe market shock linked to law enforcement activities; however, this may be best viewed as an epiphenomenon, accompanying a longer-term decline influenced by both demand and supply side factors.
During the last decade changes in opium production in Afghanistan generated a concern that a potential ‘flood of heroin’ could enter the European market. To date, no evidence exists that this has happened and, conversely, the question has become whether Europe, in part or as a whole, has recently experienced a heroin shortage.
In late 2010, information began emerging that disruption was occurring in the European illicit heroin market. These accounts were difficult to reconcile, often anecdotal and inconsistent. They included reports of injectors switching to new substances, including cathinones, increased use of benzodiazepines and the appearance of novel synthetic opiates. Most consistent were media reports from Ireland and the United Kingdom, which pointed to a dramatic reduction in heroin availability. These accounts tended to focus on the perceived negative impact of the event, which included increased risk behaviour and the use of adulterated drugs. These themes were developed in the specialized press who were more analytical, suggesting, for example, that not all parts of the United Kingdom and Ireland were affected equally . The lack of supporting empirical data and poor coherence between reports generated initial scepticism that this had wider significance. However, in winter 2010–11 health alerts were issued in both Ireland  and the United Kingdom  and corroborative data began to emerge from forensic science and law enforcement sources. From a European Union (EU) perspective, the evidence was now sufficient to prompt a wider investigation, which also provided an opportunity to pilot methods, currently in development, to report on emerging trends more rapidly . While the findings from this exercise require further review as more data become available, the exercise not only reduced levels of uncertainty but also highlighted issues where our current understanding was inadequate. Perhaps the most basic of these was the differing conception of ‘normal’ levels of heroin availability that existed between countries.
A relatively consistent picture emerged across the sources used, showing that some European countries experienced a notable heroin shortage between November 2010 and March 2011, with a partial rebound occurring after this date. It is important to note that a number of countries did not experience a shortage during this period. The countries in which market disruption occurred include Bulgaria, Ireland, Hungary, Slovenia, Slovakia, the United Kingdom and Croatia. The evidence is less clear, but suggestive, for Greece, Romania, Cyprus and Russia. In Finland and Estonia the market had already largely collapsed before 2010. In contrast, in Germany, Spain, France, Portugal, Austria and possibly the Netherlands, no major changes have been observed—a caveat being that in some of these countries heroin purity is low or has fallen. A complicating factor to this analysis is that the dramatic market shock experienced by some countries may have to be viewed as an epiphenomenon, accompanying a longer-term decline.
While it is not possible here to review all the data available to support this conclusion, an illustrative window is provided by drug testing data from Ireland and the United Kingdom. In both countries, large numbers of biological samples from treatment attendees and those in the criminal justice sector are tested. These data reveal a 50% drop in the number of positive tests for heroin between October 2010 and February 2011. The Irish data mirror the United Kingdom figures, but with the drop occurring slightly later (December and January).
An emerging hypothesis is that we need to differentiate between a longer-term market slide and shorter-term shocks. A number of countries experienced disruption to availability following the imposition by the Taliban of a ban on opium production in 2001. This earlier shock seems to have resulted in irrevocable changes, with this period seeing the establishment of fentanyl in Estonia, and buprenorphine in Finland, as heroin alternatives. Following this, both demand and supply side factors may have contributed to a longer-term reduction in availability; these include an ageing population, expansion in treatment, increasing availability of synthetic opioids and competition from other markets.
A number of fairly recent events, such as reduced production due to unfavourable weather and poppy blight, floods in Pakistan and fighting in Afghanistan, are likely to have contributed to a medium-term market squeeze. Regarding the more acute period of severe heroin drought experienced by a small number of countries, these appear to be countries associated with the same supply networks, and ‘quality arrests’ resulting from cooperation between Turkish and British law enforcement seem to have been significant . This is supported by forensic data showing that heroin transported through other countries was not affected. Taken together, the evidence suggests a long-term slow decline, or slide, in the European market starting around 2002, a more recent and generalized squeeze and finally a dramatic shock, affecting only some countries where the market was dominated by heroin transhipped through Turkey.
At the time of writing, the United Nations Office on Drugs and Crime (UNODC) reports increased opium production in 2011 . This needs to be seen against the reduction in 2010 and thus represents, to some extent, a predictable return to normal. Moreover, intelligence sources indicate that new or reorganized trafficking networks have become operational, and this is reflected in some increase in heroin availability and purity in those countries affected by the market shock.
A more challenging conclusion from our analysis is that demand and supply side factors may now be creating the conditions that could see a significant decline in Europe's heroin market. Predicting the future is difficult—but it is no longer inconceivable that the next decades will see heroin becoming a far less important part of Europe's drug problem. If this is the case, it is also likely that synthetic opiates and the injection of synthetic stimulant drugs will become, depressingly, a more important part. The only detailed analysis of a previous heroin drought comes from Australia [7,8], a country that has developed some innovative surveillance approaches . Elsewhere, data sources that permit the illicit drug market to be monitored effectively remain poorly developed. It is therefore at least possible that drug markets are becoming more volatile than is usually thought to be the case. If this is true, we may not only be failing to notice the ‘elephant in the room’, but also missing the important times when it has made itself absent.