How the drug gets a grip on users

CRITICS CLAIMED that the cult movie Trainspotting glamorised heroin, but any addict will admit that there is nothing remotely glamorous about sticking needles into your arm for a short-lived high.

One of the most addictive drugs in the world, heroin comes in the form of white or brown powder. It is traditionally injected into a vein, but can also be snorted, smoked or swallowed. Casual users say it gives a warm, mellow glow that helps them deal with stress. Higher doses act like a sedative, depressing the activity of the nervous system and slowing breathing and heart rate. Even greater amounts bring on a stupor and can knock the user out.

Most of the heroin in Britain comes from the "Golden Crescent" - the mountainous areas of Iran, Pakistan and Afghanistan where opium poppies flourish. Farmers extract a liquid from the seed head, which produces opium that can be processed into heroin. It is smuggled through the Balkans and into Britain via ports and airports.

As a Class A drug - in common with cocaine, Ecstasy and LSD - those importing heroin face up to 20 years in prison if caught. Couriers, who are paid by the importers to bring in smaller amounts, often in condoms that they swallow, can be sent down for 10 years.

If the heroin passes through Customs undetected it is broken up through a network of dealers who sell it on in smaller amounts after mixing it with other substances. Once on the street it is known variously as smack, brown, junk or skag.

Its purity often varies and many deaths have resulted from overdosing on unusually high purity. A "wrap" - enough for one smoke - sells for about pounds 10. Although those taking the drug do not inevitably become dependent on it, recreational users are often tempted to take it more regularly. As Trainspotting showed, coming off heroin is extremely difficult.

Heroin: the facts

#t Deaths from heroin in England and Wales have risen from 55 in 1993 to 194 in 1997.

t There are about 40,000 known addicts in Britain, but the total could be five times higher.

t In 1997 2,235kg of the drug were confiscated - twice the previous year.

t Heroin is commonly sold in pounds 10 wraps but can be bought for only pounds 5. Users spend an estimated pounds 3bn on the drug every year.