Cannabis remains the most commonly used illicit drug in Croatia. A 2015 survey indicated that approximately one in five adults aged 15-64 years have used cannabis at least once during their lifetime. Cannabis use is concentrated among young adults (aged 15-34 years). Approximately 2 in 10 younger adults aged 15-24 years reported using cannabis at least once during the last year, while approximately 1 in 50 of the same age group had used amphetamines, which are the most commonly used stimulants, in the last 12 months. Males generally use illicit drugs more frequently than females.
Zagreb participates 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. Regarding stimulants, the results indicate a continued increase in cocaine use in Zagreb in 2011-17, with the levels being higher at the weekends than on weekdays. The increasing trends for amphetamine and MDMA/ecstasy over the 2011-15 period seem to have stabilised in recent years. The levels of methamphetamine metabolites measured in wastewater remained low during the observation period, indicating limited use of this substance in the city.
Data on drug use among 15- to 16-year-old students was reported in 2015 by the European School Survey Project on Alcohol and Other Drugs (ESPAD). This study has been conducted in Croatia since 1995. Among Croatian students, reported prevalence rates were considerably higher than the ESPAD averages (35 countries) for five of the eight key variables, one of which was lifetime use of cannabis. Available data indicate an upward trend in cannabis use among school-age children between 2001 and 2015.
Reported lifetime use of new psychoactive substances (NPS) among 15- to 16-year-old students was also slightly above the EU average, while lifetime use of illicit drugs other than cannabis was at the level of the European average. In 2015, Croatian students reported higher levels of lifetime use of inhalants and of cigarette use in the last 30 days. In addition, alcohol use and heavy episodic drinking in the last 30 days were above the ESPAD averages.
The emergence of the use of NPS is one of the primary concerns in Croatia. The available data indicate that approximately 7 in 100 students and the same proportion of young adults (aged 15-24 years) have tried NPS during their lifetime.
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 and of trends in high-risk drug use.
In 2015, a mortality multiplier study estimated that the total population of high-risk opioid users was approximately 8 900 (3.09 per 1 000 population). The same study indicated that there were 6 344 people who inject drugs in Croatia (2.21 per 1 000 population).
Data from specialised treatment centres show that the majority of first-time treatment entrants report cannabis as their main primary problem drug; they are followed by those seeking treatment as a result of primary heroin use. In the last decade, the number of first-time treatment entries as a result of heroin use has decreased by almost 90 %, although heroin remains the main problem drug for which people seek treatment in Croatia. Injecting remains common among heroin users, although first-time treatment clients report lower levels of heroin injecting than those who have entered treatment repeatedly. Fewer than 2 in 10 people entering treatment are female, with the exact proportion varying according to substance type and programme.