The data presented in this paper describe trends in treated problem drug use in Ireland between 2001 and 2006. The paper describes treated problem drug use in relation to person, place and time.

The analysis presented is based on data reported to the National Drug Treatment Reporting System (NDTRS) and to the Central Treatment List (CTL). It is important to note that the NDTRS collects data on episodes of treatment, rather than the number of individual people treated each year. This means that individuals may appear in the figures more than once if they attend more than one treatment service in a year, and may reappear in subsequent years.