A 2010 study in the British Journal of Criminology on the “”Portugal Model”” is being cited in support of decriminalizing illicit drugs in the United States.

But John Carnevale, Ph.D., a veteran of the Office of National Drug Control Policy (ONDCP) through four drug czars, issued a March 22 policy brief arguing that the authors’ conclusions are weak and contradictory, and that drug policy in general is difficult to translate from one country to another.

The research article focused on the impact of two policies Portugal implemented between 1999 and 2001 — one decriminalized possession of illicit drugs, and the other significantly increased access to substance abuse treatment by diverting “”minor drug offenders”” to treatment. This is the Portugal Model.

The authors argued that the Portugal Model shows that decriminalization does not necessarily lead to significant “”increases in the most harmful forms of drug use,”” but Carnevale cited numerous problems with the research. Among them:

• As the authors themselves observed, “”numerous challenges ‘make it impossible to attribute any changes in drug use or related harm directly to the fact or form of the Portuguese decriminalization.’”” They noted, for instance, that it was not possible to determine whether effects observed during the study period were causally linked to decriminalization or to the increased availability of treatment, in part because they were introduced around the same time.
• Were the policies altogether positive? Carnevale argued that they were not. Although the study’s authors documented that “”problematic drug use, particularly IV drug use”” dropped, that drop was not statistically significant, and overall drug use by adults soared 53 percent between 2001 and 2007, rising from 7.8 percent to 12 percent.
• Portugal saw enrollments in drug treatment jump 63 percent during the study period – but, Carnevale said, there’s no correlation between increased treatment enrollment and decriminalization. Instead, Portugal’s implementation of diversion programs for drug offenders was the likely reason for the increase. 

Carnevale concluded, “”This study’s findings fail to offer insight into the effects of Portugal’s decriminalization policies within its own borders. Therefore, it is impossible for us to recommend it be used as a basis for any policymakers, in any country, to justify moving toward decriminalization.””