Within the United Kingdom, data from England and Wales show that drug misuse was responsible for 10 percent of deaths from all causes for those aged 20-39 in 2011.

Heroin and morphine accounted for most of the deaths, but between 2010 and 2011 the number of deaths associated with these two drugs declined by 25 per cent, from 791 to 596. This decline might have been associated with the heroin “drought” experienced in the United Kingdom starting in 2010. However, over the same time period, the number of deaths related to the use of methadone, reportedly mixed with benzodiazepines and/or alcohol, increased by 37 per cent, from 355 to 486.

A similar situation was observed in Scotland, where there was a 19 per cent decline in the number of deaths involving heroin and morphine, from 254 in 2010 to 206 in 2011, with a simultaneous 58 per cent increase in the number of deaths associated with methadone, from 174 in 2010 to 275 deaths in 2011.

Across the United Kingdom, the involvement of multiple substances implicated in drug-related deaths, notably the use of opiates/opioid analgesics, benzodiazepines and alcohol, has been noted, highlighting the increased risk associated with polydrug use.

Source:  World Drug Report 2013  www.unodc.org  June 2013