To know the prevalence of consumption of different psychoactive drugs and other related behaviours, to find out the socio-demographic characteristics of users, to find out the patterns of consumption of psychoactive substances, to find out the availability of drugs as perceived by the population and the perceived risk of different drug-taking behaviours, to find out the visibility of drug problems in the place where respondents live, to find out the population's opinion about the importance of drug use problems and measures to reduce them.