"Afghanistan maintained its position as the lead producer and cultivator of opium globally. With a global total of over 236,000 hectares under cultivation, illicit cultivation of opium poppy reached peak levels in 2012, surpassing the 10-year high recorded in 2007. This was mainly the result of increases in Afghanistan and Myanmar (the two main producers). A preliminary assessment of opium poppy cultivation trends in Afghanistan in 2013 revealed that such cultivation is likely to increase in the main opium growing regions, which would be the third consecutive increase since 2010.62 Mexico remained the largest grower of opium poppy in the Americas. An overview of global potential production of opium and manufacture of heroin, as well as country data on opium poppy cultivation and eradication and opium production can be found in Annex II.
"The fluctuations which characterized opium production in Afghanistan in recent years, also affected Europe, the main market for opiates. Heroin use decreased in Western and Central Europe, which can be ascribed to a change in the structure of the market, which has seen decreased supply, increased law enforcement activity and an ageing user population, combined with an increase in the availability of treatment. However, the same does not apply to the non-medical use of prescription opioids."
UNODC, World Drug Report 2013 (United Nations publication, Sales No. E.13.XI.6), p. 30.