Health fears grow for cannabis users as report warns 'marijuana potency is stronger than ever'

A study backs evidence in Britain that today’s cannabis is effectively a different drug to
that of the 60s and 70s, and underlines fears about the psychiatric problems it causes.

White House drug czar John Walters warned 'baby boomer' parents who were in their teens and 20s during those decades that they were wrong to think the modern drug was as weak as the marijuana they may have smoked.

Marijuana potency has reached its highest levels in 30 years, according to a White House report

‘This report makes it more important than ever that we get past outdated, anachronistic views of marijuana,’ he said.

‘Marijuana potency has grown steeply over the past decade, with serious implications in particular for young people.'

The report  will strengthen the UK lobby for Britain’s ‘softly softly’ policy on cannabis to be reversed. Labour downgraded it from a Class B to a Class C drug in 2004, but a growing number of experts believe it should be returned to its previous status.

The American findings reflect growing evidence in the UK that cannabis - particularly the common and particularly potent form of the drug known as ‘skunk’  - is far stronger than previously thought.

The study also underlined fears raised earlier this year by Professor Louis Appleby, Britain’s national director for mental health, over the ‘severe’ psychiatric problems caused by cannabis.

Concerns have been raised about the strength of marijuana despite some users claiming it is 'harmless'

The U.S. study said marijuana use increased the risk of developing mental disorders by 40 per cent.

‘The increases in marijuana potency are of concern since they increase the likelihood of mental impairment,’ said Dr. Nora Volkow, director of the National Institute On Drug Abuse, which funded the report.

She said there were fears that the increased strength might trigger changes in the brain that can lead to addiction.

The White House blames the increases in marijuana potency to sophisticated growing techniques that drug traffickers are using at sites in the United States and Canada as they try to gain a product with a bigger ‘kick’.

The new report is based on analysis from the University of Mississippi’s Potency Monitoring Project, which tracked the average amount of THC, the psychoactive ingredient in marijuana, in samples seized in drug raids over the last 30 years.

It showed that the average amount of THC reached 9.6 per cent in 2007, more than  doubling the potency in 1983, when it averaged just under four per cent.

Walters, director of the White House Office of National Drug Policy, singled out ‘misguided’ baby boomer parents who still believe the drug has the same potency it had in the '70s and warned of marijuana’s potential as a gateway  drug to heroin and cocaine.

He also warned of the increased risk of psychological, cognitive and  respiratory problems faced by cannabis users.