The prevalence of use of illicit substances in Spain has been relatively stable in recent years, with more than one third of the adult population reporting lifetime use of an illicit substance. Cannabis is the most commonly used drug, with use mainly concentrated among adolescents and adults younger than 35 years. The prevalence of use of the most commonly consumed illicit drugs (cannabis and cocaine) showed a downward trend until 2017, when an increase was observed for both substances. The use of all illicit substances remains more prevalent among males than females.
In 2017, 1 in 100 adults aged 15-64 years reported the use of new psychoactive substances. Most users of this type of substance were male and young and reported polydrug use (with other legal and illegal psychoactive substances).
The Spanish cities of Barcelona, Castellón, Madrid, Santiago and Valencia participate in the Europe-wide annual wastewater campaigns undertaken by the Sewage Analysis Core Group Europe (SCORE). This study provides data on drug use at a municipal level, based on the levels of illicit drugs and their metabolites found in wastewater. The results of the 2018 study on stimulant drugs revealed high levels of cocaine metabolites in wastewater samples from all five cities, higher than the levels reported in some other European cities participating in the study. In addition, Barcelona recorded an increase in MDMA/ecstasy, amphetamine and methamphetamine residues between 2011 and 2018. A common pattern across the monitored cities was increased use of cocaine and MDMA at the weekends.
Data on drug use among 14- to 18-year-old students are drawn from the Spanish Survey on Drug Use in Secondary Schools (ESTUDES), which has been conducted every second year in Spain since 1994. The 2016 survey reported that the most commonly used illicit substance is cannabis, with about 3 out of 10 students reporting lifetime use. No changes were observed in the proportion of students who had used cannabis in the preceding 30 days. Lifetime prevalence rates for use of other illicit drugs among students remain well below that for use of cannabis. ESTUDES also supplies data to the European School Project on Alcohol and Drugs (ESPAD), and the 2014 data indicated that prevalence of lifetime cannabis use among Spanish students aged 15-16 years was higher than the ESPAD average (based on data from 35 countries).
Studies reporting estimates of high-risk drug use can help to identify the extent of the more entrenched drug use problems, while data on first-time entrants to specialised drug treatment centres, when considered alongside other indicators, can inform an understanding of the nature of and trends in high-risk drug use.
In Spain, heroin remains the main substance linked to the most serious adverse health and social consequences, such as drug-related infections. The estimated number of high-risk heroin users has shown a decreasing trend between 2010 and the latest estimate in 2016. The prevalence of injecting drug use was estimated to be 0.41 per 1 000 in 2016.
Data from specialised treatment centres indicate that cocaine remains the substance resulting in the highest number of all treatment entries, with the number of first-time clients reporting cocaine as the primary substance of use having increased in 2015 and 2016, following a long period of decline. Only a small proportion of cocaine users entering treatment reported injecting drug use. Further data from treatment centres indicate that, after increasing substantially up to 2013, the number of first-time cannabis treatment demands has since declined.