Methodological note: Analysis of trends is based only on those countries providing sufficient data to describe changes over the period specified. The reader should also be aware that monitoring patterns and trends in a hidden and stigmatised behaviour like drug use is both practically and methodologically challenging. For this reason, multiple sources of data are used for the purposes of analysis in this report. Caution is therefore required in interpretation, in particular when countries are compared on any single measure. Detailed information on methodology and caveats and comments on the limitations in the information set available can be found in the EMCDDA Statistical Bulletin.
Additional note for the Netherlands: Data on number and quantity of seizures do not include all relevant law enforcement units and should be considered partial, minimum figures. Data for amphetamines, heroin and MDMA include seizures by Dutch Customs and the Royal Military Police, but do not include seizures by national or regional police forces. Cocaine seizures represent the majority of large seizures, comprising data from Dutch Customs (including Rotterdam and Vlissingen harbours), the Royal Military Police and the National Police Force, but regional police force data are not included. Cannabis data are limited to police seizures of plants, cuttings and tops seized during dismantlement of cultivation sites. Data on precursors (scheduled and non-scheduled substances) are based exclusively on reports of suspicious transactions of such substances to the Fiscal Intelligence and Investigation Unit.