Alan Travis
Skunk strength has doubled, studies suggest | · Claims that super-strength variety dominant rejected · Cannabis researchers analysed seized samples
The Guardian, Monday 17 September 2007
The unpublished results of authoritative research into cannabis confirm the "skunk" now on sale in England is stronger than it was a decade ago, but demolish claims that a new "super-strength skunk" - which is 20 times more powerful - is dominating the market.
Two studies due to be published later this year, which together analysed nearly 550 samples of skunk seized by the police, both conclude that the average content of the main psychoactive agent in skunk strains of cannabis, THC, has doubled from 7% in 1995 to 14% in 2005.
But the findings of the two studies to be reported in Druglink, the drugs charity magazine, contradict recent claims that most of the skunk on sale in Britain now routinely has a THC-content of more than 30%. One of the studies showed that only 4% of the skunk that had been seized by the police had a strength level higher than 20%.
The claims earlier this year that a new strain of "super-strength skunk" cannabis that was up to 20 times more potent was dominating the British drug market and triggering mental health fears led Gordon Brown to order a new review of the legal status of the drug in July.
The home secretary, Jacqui Smith, asked the government's advisory council on the misuse of drugs (ACMD) to look at the current evidence on the use of stronger forms of the drug in the light of concerns about the potential mental health effects.
The ACMD last looked at whether to regrade cannabis as a class B rather than a class C illegal drug 18 months ago. It concluded that the strength of cannabis resin and "traditional" imported herbal cannabis had remained unchanged over the past 10 years but that the average potency of skunk or sinsemilla seizures had increased more than twofold.
However, the ACMD chairman, Professor Sir Michael Rawlins, came down against tightening up the penalties for using cannabis, saying there was too little information about the pattern of use of different strength cannabis products by consumers to change the law.
Recent evidence has shown that although there has been an explosion in cannabis farms and "home-grown" plants in Britain, little of what is produced is "super-strength skunk".
The majority is less potent but has higher yielding varieties.
The ACMD is due to give its new verdict in April next year.
The first of the two unpublished studies which appear to confirm those findings was by Leslie King, the former head of the Forensic Science Service's drugs intelligence unit. He tested 299 samples collected by forensic scientists and his findings are to be published later this year by the EU's drug agency, the European Centre for Drugs and Drug Addiction.
The parallel study by researchers at Kings College, London, analysed skunk samples seized by police in Derbyshire, Kent, London, Sussex and Merseyside. This study found that far from a new strain of 30% plus "superskunk" dominating the market only 4% of the cannabis seized had a higher potency level than 20%, with the strongest sample containing 24% THC.
The Kings College researchers found that the more traditional non-skunk strains of herbal cannabis on sale in England seized by the police contained only 3% to 4% THC - unchanged from a decade ago.
A move to have higher separate penalties for possession of the stronger "skunk" strains of cannabis was ruled out two years ago in the face of the problem posed for the police of identifying different types of cannabis during street searches.
In numbers
20 Claims that a new 'super' skunk is 20 times stronger are demolished
30% Most skunk on sale had been said to contain more than 30% THC
550 The number of seized samples of skunk analysed in the two studies
14% Average THC content in samples
4% Only 4% of skunk seized had THC of over 20%, one study showed