This paper describes trends in treated problem drug use in Ireland between 2005 and 2010. 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 each record in the NDTRS database relates to a treatment episode (a case), and not to a person. This means that the same person could be counted more than once in the same calendar year if he/she had more than one treatment episode in that year.

The main findings of the analysis are:
• The total number of cases in treatment for problem drug use increased over the reporting period, from 12,101 in 2005 to 16,429 in 2010.
• The number of cases entering drug treatment each year and reported to the NDTRS increased by 52%, from 5,176 in 2005 to 7,878 in 2010. The clear spread and increase in treated drug use throughout the country reflect not only the extent of problem drug use but also an increase in treatment availability and compliance with the NDTRS.
• Both the incidence (new cases) and the prevalence (all cases) of treated problem drug use among 15–64-year-olds living in Ireland increased consistently over the reporting period. The incidence increased from 70 cases per 100,000 in 2005 to 106 cases in 2010. The number of new cases entering treatment is an indirect indicator of recent trends in problem drug use. The prevalence increased from 423 cases per 100,000 in 2005 to 544 cases in 2010.
• There was an increase in the total number of drug treatment services available in Ireland and participating in the NDTRS between 2005 and 2010. In the six-year period, the majority (68%) of cases received treatment in outpatient settings. Of the 7,878 cases who entered treatment in 2010, the majority (58%) received counselling, 32% received a brief intervention, 25% received methadone substitution and 23% attended education/awareness programmes.