Is abandoning the war on drugs the way to win it? How Portugal's pioneering approach delivered results

For ITV's On Assignment, Geraint Vincent travelled to Lisbon to find out if the way to win the war on drugs is to stop fighting it.

Portugal led the world when it decriminalised the use of all drugs – everything from marijuana to heroin - in 2001. It was a response to a national crisis in which one in every ten people had a drug problem.

Today, authorities don’t arrest anyone with up to a 10-day personal supply, drug use carries no stigma and there have been dramatic drops in overdoses and HIV infections.

Anyone in Portugal can possess one gram of heroin, two of cocaine, 25 of grams of marijuana leaves, five of hashish and one gram of ecstasy without any punishment.

The focus has shifted from the substance itself, to the user’s relationship with that substance. That is now dealt with in office blocks rather than courtrooms. People caught with more than ten days’ personal supply have to attend what’s known as a ‘dissuasion panel’.

Another way the government manages the country's drug problem is providing addicts with the heroin substitute methadone from vans. Visiting one of these vans has been part of Carla’s morning routine for seven years. She goes there on her way to work. The programme has saved her life, she says.

• Watch Geraint's full report in this week's On Assignment, broadcast at 11.50pm on ITV on Monday 11th June