"In the Portuguese case, the statistical indicators and key informant interviews that we have reviewed suggest that since decriminalization in July 2001, the following changes have occurred:
"• small increases in reported illicit drug use amongst adults;
"• reduced illicit drug use among problematic drug users and adolescents, at least since 2003;
"• reduced burden of drug offenders on the criminal justice system;
"• increased uptake of drug treatment;
"• reduction in opiate-related deaths and infectious diseases;
"• increases in the amounts of drugs seized by the authorities;
"• reductions in the retail prices of drugs.
"By comparing the trends in Portugal and neighbouring Spain and Italy, we can say that while some trends clearly reflect regional shifts (e.g. the increase in use amongst adults) and/or the expansion of services throughout Portugal, some effects do appear to be specific to Portugal. Indeed, the reduction in problematic drug users and reduction in burden of drug offenders on the criminal justice system were in direct contrast to those trends observed in neighbouring Spain and Italy. Moreover, there are no signs of mass expansion of the drug market in Portugal. This is in contrast with apparent market expansions in neighbouring Spain."


Hughes, Caitlin Elizabeth and Stevens, Alex, "What can we learn from the Portugese decriminalization of drugs?" British Journal of Criminology (London, United Kingdom: Centre for Crime and Justice Studies, November 2010), Vol. 50, Issue 6, p. 1017.