As Californians prepare to vote on whether to legalize marijuana possession in the state, it may be worth looking to Europe to see how liberal drug policies work — specifically in Portugal, where the possession of drugs has not carried a criminal penalty since 2001. (Watch a report about Portugal's loose drug laws.) Here is a look at how decriminalization has helped — and hindered — Portugal's war against drug abuse:

Why did Portugal decide to decriminalize drugs?
During the 1990s, the country had one of the highest rates of hard-drug use in Europe, with 100,000 heroin addicts. Instead of cracking down on drug abusers, the government decriminalized the possession of drugs for personal use in June 2001. "The idea is to get away from punishment toward treatment," a government spokesperson said at the time.

What happens if you are caught using drugs in Portugal?
Drug users must meet with a panel of psychologists, social workers, and legal advisors, and agree to undergo treatment for addiction instead of going to prison. This penalty covers all recreational drugs, from marijuana to heroin. Possession over a certain amount can still land you in jail, as can dealing and trafficking.

Did it work?
It depends on whom you ask. According to libertarian think tank the Cato Institute, illegal drug use among Portuguese teenagers declined after 2001, and 45 percent of the country's heroin addicts sought medical treatment. Marijuana use in particular has plummeted — only 10 percent of Portuguese adults are now pot smokers, less than the proportion of Americans who are regular cocaine users. But critics of the policy, such as the Association for a Drug-Free Portugal, say overall consumption of drugs in the country has actually risen by 4.2 percent since 2001 and claim the benefits of decriminalization are being "over-egged.

What lesson could this have for California, and the U.S. as a whole?
Imposing a "Portugal plan" would be a "major step in the right direction" for California, says Bob Morris at California Independent Voters Network. Decriminalizing or legalizing drugs would break the hold of Mexican drug cartels, and thousands of former druggies would become "law-abiding taxpayers" rather than prison-bound wards of the state. But others say it could never happen in the U.S. "The war on drugs is a real industry, especially where prisons have been privatized," says AIDS expert Dr. Evan Wood, quoted in AOL News. The result is a "political quagmire" whenever decriminalization is mentioned.

Sources: BBC, Time, Guardian, AOL News