Probably more accurate tracking since no penalty for truthful response. No comparison to aspirin, OldVet. But what I see contradicts CaveJohnson's claim: reported use is way up, again, probably due to greater candor in response.
On the positive side are the findings from here or here:
Drug use among adolescents (13-15 yrs) and "problematic" users declined.
Drug-related criminal justice workloads decreased.
Decreased street value of most illicit drugs, some significantly.
Decriminalizing Drugs in Portugal a Success, Says Report - TIME
"Compared to the European Union and the U.S., Portugal's drug use numbers are impressive. Following decriminalization, Portugal had the lowest rate of lifetime marijuana use in people over 15 in the E.U.: 10%. The most comparable figure in America is in people over 12: 39.8%. Proportionally, more Americans have used cocaine than Portuguese have used marijuana.
The Cato paper reports that between 2001 and 2006 in Portugal, rates of lifetime use of any illegal drug among seventh through ninth graders fell from 14.1% to 10.6%; drug use in older teens also declined. Lifetime heroin use among 16-to-18-year-olds fell from 2.5% to 1.8% (although there was a slight increase in marijuana use in that age group). New HIV infections in drug users fell by 17% between 1999 and 2003, and deaths related to heroin and similar drugs were cut by more than half. In addition, the number of people on methadone and buprenorphine treatment for drug addiction rose to 14,877 from 6,040, after decriminalization, and money saved on enforcement allowed for increased funding of drug-free treatment as well."
It's pretty much been a success across the board.
"Those data indicate that decriminalization has had no adverse effect on drug usage rates in Portugal, which, in numerous categories, are now among the lowest in the EU, particularly when compared with states with stringent criminalization regimes. Although postdecriminalization usage rates have remained roughly the same or even decreased slightly when compared with other EU states, drug-related pathologies — such as sexually transmitted diseases and deaths due to drug usage — have decreased dramatically. Drug policy experts attribute those positive trends to the enhanced ability of the Portuguese government to offer treatment programs to its citizens — enhancements made possible, for numerous reasons, by decriminalization."
I shouldn't have said "rates of abuse dropped" I basically was trying to say, it's working as opposed to keeping things illegal. Should've been more clear, but they've still gone down.