Cannabis: super-strength me

For some while now, the international consensus on cannabis has been breaking down. According to the Single Convention on Narcotic Drugs, now over forty years old, signatory countries are supposed to treat cannabis no different legally than heroin or cocaine. Nor does international law recognise any medical benefits from the use of cannabis. But over time, and in the full knowledge of how difficult it is to get treaties amended, countries have been breaking ranks, by reducing the penalties for personal possession even down to administrative rather than criminal offences, although none have gone so far as the Dutch in allowing the sale of cannabis in specially designated premises.

Even the American government, who dominate the conduct of international drug policy, was unable to prevent eleven States decriminalising the drug in the 1970s, policies which were eventually reversed only when the incoming Republican government threatened withdrawal of Federal funding. Still today, the Federal authorities are at odds with some States who are allowing the sale of cannabis for medical purposes.

So a new battle has been joined to win over the hearts and minds of the general public as to the dangers of cannabis, by claims that cannabis is fifty or a hundred times stronger than it used to be, that it is simply a different drug and so we must redouble our efforts to curb its use.

There is strong cannabis in circulation - and ironically as a direct result of enforcement efforts. The widespread spraying of outdoor cannabis crops in the USA, prompted the growers to develop much smaller, indoor varieties and using horticultural techniques produced cannabis with a higher THC level than was usually available. The techniques were copied in Europe and now we have a highly profitable commercial home grown cannabis market using exploited immigrant labour to tend the plants. See the March/April issue of Druglink for an exclusive feature on this.

But cannabis has been available in widely varying strengths for many years. Some of the claims for the increased potency of cannabis are based on comparisons with very low grade US government-grown cannabis tested by the University of Mississippi in the mid 1970s. Yet during the same period, cannabis grown by US commecial growers could range up to 10% in THC content. In 1997, the World Health Organisation said, 'THC content in hashish ranges from 2-8%, although may be as high as 10-20%'. European research published in 2004 concluded that claims about recent significant increases in cannabis potency were unsubstantiated. And 2004 data from the US government puts the average rise in cannabis potency at only double, from 3.5% in 1985 to 7% in 2003.

Cannabis remains a potentially dangerous drug for those with mental health problems and adolescent services are more likely to see troubled young people self-medicating with alcohol and cannabis than heroin or crack. Also we know very little about the UK's cannabis using population. We don't know details about their buying habits, how easy it is to buy the higher THC brands, whether users really want a very strong experience, the price range for different brands, how many types are currently available in the UK, to what extent buyers and sellers are aware of THC content in a particular batch, what the cannabis consumer's perception is of imported hash and so on. Nor do we have any information on how THC levels relate to risk. Is a joint with 8% THC double the risk of one with 4% THC?

People should be aware of potential harms of cannabis. But as the Home Affairs Select Committee said in 2002, ' we do not believe there is anything to be gained from exaggerating its harmfulness'.