"In 2018, an estimated 269 million people worldwide had used drugs at least once in the previous year (range: 166 million to 373 million). This corresponds to 5.4 per cent of the global population aged 15–64 (range: 3.3 to7.5 per cent), representing nearly 1 in every 19 people.

"Over the period 2009–2018, the estimated number of past-year users of any drug globally increased from 210 million (range: 149 million to 272 million) to 269 million (range: 166 million to 373 million) – in other words, by more than a quarter (28 per cent) – partly as a result of growth in the global population. Consequently, the prevalence of drug use increased by over 12 per cent, from 4.8 per cent (range: 3.4 to 6.2 per cent) of the adult population in 2009 to 5.4 per cent (range: 3.3 to 7.5 per cent) in 2018. However, considering the wide uncertainty intervals of these estimates and that in any given year the global estimates represent the best available data, any comparison of the estimates over time should be undertaken with caution."


World Drug Report 2020 (United Nations publication, Sales No. E.20.XI.6).