"Similarly to previous surveys, cannabis was the most commonly used drug by respondents in the 2018/19 CSEW, with 7.6 per cent of adults aged 16 to 59 having used it in the last year, equating to around 2.6 million people. As shown in Figure 1.4 below, there was a long-term decline in the proportion of adults who used cannabis in the last year, decreasing from a high of 10.7 per cent in 2002/03 to 6.5 per cent in 2009/10. The trend was then relatively flat until 2016/17 but has since shown a one percentage point increase in last year use of cannabis, to 7.6 per cent in 2018/19.

"Cannabis was also the most commonly used drug by young adults aged 16 to 24, with 17.3 per cent having used it in the last year according to the 2018/19 CSEW (around 1.1 million young adults). The long-term decline in prevalence of cannabis use in the last year was more apparent in this age group, falling from 28.2 per cent in 1998 down to 15.1 per cent in the 2013/14 survey. Since then there has been a general upward trend although the latest estimate is similar to the previous year (2017/18 CSEW, 16.7%)."


Drug Misuse: Findings from the 2018/19 Crime Survey for England and Wales. Statistical Bulletin 21/19. National Statistics. Home Office. 19 September 2019.