Meth abuse is particularly bad in rural areas of the US

A survey of 500 county law enforcement agencies found meth-related arrests had gone up over the past three years.

More than half of the police, sheriff departments and other agencies polled said the highly addictive substance was their biggest drug problem.

Less than 20% singled out cocaine and fewer still pointed to marijuana.

Highly addictive

Methamphetamine is a chemical variant of amphetamine with much more powerful effects.

METHAMPHETAMINE Sold as powder, tablets or crystals Can be snorted, smoked, injected or swallowed Can alter personality; increase blood pressure and damage brain

Abuse is particularly bad in rural areas.

It is easy to produce using chemicals found on farms, and the homemade labs which produce it are less easy to detect in the countryside.

The findings are based on figures collated from rural and suburban areas and do not include most of the country's largest cities.

Half of the counties surveyed said 20% of people in their jails were there because of meth-related crimes.

In some places it accounts for more than 50% of people detained, and law enforcement officials say burglaries, domestic violence and assaults have increased because of it.

The problem started in the northwestern US, but it is moving east - and it is now having what the Washington-based National Association of Counties (Naco) calls a "devastating" effect on communities nationwide.

"Methamphetamine abuse is mainly a rural and suburban problem but it is slowly moving to the cities," Naco research director Jacqueline Byers told the BBC news website.