* In 2012 there were 3,971 people entering treatment who were mostly addicted to heroin.
* Heroin was implicated in 72 deaths in 2010 and 60 in 2011, more than one in five of all poisoning deaths.
* There were 13 new cases of HIV among injecting drug users in 2012, down from 71 in 2004.
* In 2011 the heroin substitute methadone was implicated in 113 deaths, compared with 60 in 2010.
* The percentage of adults who had ever used cannabis rose from 21.9pc in 2006 and 2007 to 25.3pc in 2010 and 2011.
* Cannabis, including cannabis herb, plants and resin, accounts for the largest number of drug seizures in Ireland. There were 2,912 seizures in 2012, one in two of all drug seizures.