" The estimated prevalence of problem drug use amongst 15 to 64 year olds in Scotland has increased from 1.62% (95% CI = 1.59% - 1.67%) in 2006 to 1.71% (95% CI = 1.67% - 1.75%) in 2009/10. Although the estimate of problem drug use prevalence was higher in 2009/10 compared to 2006, it cannot be said conclusively that actual prevalence has increased. This is due to the fact that the confidence limits shown are very close and do not take into account potential data and methodological differences between the years being compared. However, we can be reasonably sure that actual problem drug use prevalence has not declined since 2006 (Table 7).
" Looking at the change between 2006 and 2009/10 by age group there are apparent decreases in the estimated prevalence rate in both the 15 to 24 and 25 to 34 year old age groups (from 1.75% in 2006 to 1.63% in 2009/10 for 15 to 24 year olds and from 3.90% in 2006 to 3.60% in 2009/10 for 25 to 34 year olds. However, for the 35 to 64 years old age group the estimated prevalence rate appears to have increased from 0.89% in 2006 to 1.18% in 2009/10 (Table 8). This pattern seems to be reflected in data sources such as Scottish Drug Misuse Database (SDMD), hospital discharges and drug related deaths which have seen increases in older age groups and decreases in younger age groups. The percentage of new patients/clients attending drug treatment services on the SDMD aged 35 and over increased from 30% in 2006/7 to 35% in 2009/10 (Drug Misuse Statistics Scotland 2010, Table A1.3). The number of known individuals with problem drug use in treatment in 2009/10 as a percentage of the estimated prevalence of problem drug misuse is virtually unchanged from 2006 at 42%."
Scottish Government, "Estimating the National and Local Prevalence of Problem Drug Use in Scotland 2009/10" (Edinburgh, Scotland: Information Services Division, NHS National Services Scotland, Nov. 29, 2012), p. 18.