WHEN it comes to the issue of decriminalising drugs, campaigners often point to the example of Portugal as a success story.

In 2001, it decided to treat possession and use of small quantities of anything from cannabis to heroin as a public health issue, rather than a criminal one.

It means individuals caught with up to 10 days' worth of an average daily dose of illegal drugs for personal use are referred to panels which can decide how to deal with the offence – such as community service, fines or referral for treatment. Most first-time offenders without a drug problem will not face any sanctions.

According to a recent report compiled by charity Release, which focuses on drug law, the impact of the policy has been varied. Analysis seems to suggest there was a small increase in lifetime drug use among adults following decriminalisation. However, Portugal's level of drug use is still below the European average.

There have been increases in the number of drug-dependent individuals in treatment and a significant decrease in the number of drug-related deaths.

The number of criminal drug offences has dropped from around 14,000 per year before decriminalisation to around 5,500 per year. And the number of prisoners in jail due to drug-related offences dropped from 44 per cent in 1999 to 21 per cent by 2008.