Mental illness rate soars among users of skunk cannabis

In some parts of the country, the number of people suffering from mental and behavioural disorders caused by cannabis use has risen tenfold.

The number of adults admitted to hospital as a result of cannabis use is up by 73 per cent, from 430 a decade ago to 743 last year.

The areas with the highest number of hospital admissions were Manchester, London, Cheshire and Merseyside.

The increase is blamed on people smoking the highly potent "skunk" variety of the drug.

The Forensic Science Service says the stronger skunk cannabis accounts for 75 per cent of all cannabis seized.

In the Bedfordshire and Hertfordshire Strategic Health Authority area, cases of mental disorders due to use of cannabis have increased by more than 1,000 per cent, from two in 1996 to 23 last year.

Statistics from the National Treatment Agency for Substance Misuse show that more than 24,500 people are in drug-treatment programmes for cannabis use, the highest figure ever.

Cannabis misuse accounts for 75 per cent of under-18s who require treatment for drug use.

The current number of youngsters in treatment for cannabis abuse is 11,582, more than double the total in 2005, while more adults - 13,087 - are in drug treatment programmes for cannabis abuse than for crack or cocaine.

The worrying statistics pile yet more pressure on the Government to reclassify the drug to Class B, having ordered a review earlier this year.

Shadow Home Secretary David Davis said last night: "This is yet more evidence that cannabis should be reclassified and of the real harm that it is causing, especially to young people.

"The Government cannot continue to ignore the demotivating and debilitative effects this drug has. If they do, they will be guilty of betraying a whole generation."

Since Labour downgraded the drug to Class C in 2004, users no longer even face automatic arrest. Instead, police officers can simply give out a formal warning for cannabis possession on the street.

Around 66,000 such warnings were issued last year.

If the drug is pushed back to Class B, the formal warning system would be scrapped and users would face arrest and the humiliation of being taken to a police station.

Campaigners hope this would be enough to deter people from trying the drug in the first place, and send out a strong message of the harm it can do.

The re-classification, currently being considered by the Advisory Council on the Misuse of Drugs, is supported by a powerful coalition of medical experts, mental health charities, the police and magistrates.

The Magistrates' Association has warned that youth courts are full of children turned to a life of crime by the drug. Magistrates say children believe it cannot be harmful if it has been downgraded by the Government.

Last week, crime figures revealed a 14 per cent increase in drugs crime - mostly fuelled by increased cases of people being stopped with cannabis.