A European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) report – An Overview of cannabis potency in Europe (2004) states:
“Statements in the popular media that potency of cannabis has increased by ten times or more in recent decades are not supported by the limited data that are available from either the USA or Europe. The greatest long-term changes in potency appear to have occurred in the USA. It should be noted here that before 1980 herbal cannabis potency in the USA was very low by European standards”.
More information can be found on this in King’s, Carpentier’s and Griffith’s report on European Cannabis Potency - a must read piece of research in this area. They found that that "public health consequences of alcohol consumption are not a simple function of the strength of the beverage consumed, be it beer, wine or spirits. Rather, at population level, research suggests that it is the total quantity of alcohol consumed that is important rather than the concentrations in which it is sold." It is unknown how far this parallel holds for cannabis. Authors regard age of onset of use and frequency of use likely to be more influential than changes in potency in determining consumption levels. "In conclusion, we should not be unduly alarmed by the modest changes that have occurred in average cannabis potency; but neither should we be complacent, particularly as the evidence base is relatively weak and the relationship between potency, dose and problems remains poorly understood."
If it was true that cannabis potency had risen by 10% or more then we would also be seeing huge differences in other crops, have tomatoes grown by 10%? - no. Although selective cross breeding programmes have slightly increased the potency of cannabis it would be impossible to increase them by this much.
Cannabis Potency may have increased with herbal cannabis due to the following reasons:
- Selective cross breeding programmes producing hybrid strains.
- More intense cultivation techniques, e.g. hydroponic growth, prevention of fertilisation (in the creation of sinsimilla).
- Freshness – around 50% of cannabis is now produced in the UK, according to official reports when before it was being imported from abroad, commonly Africa.
- Stronger parts of the cannabis plant are being used.
There is still much research to be done on the effects of using cannabis with increased THC content – we will endeavour to reproduce this as it becomes available.
We also would like to encourage research into the cannabinoid ration of differing types of cannabis to see how they effect us.
Further Research:
Potency Differences in Plant parts
How Marijuana Works
Dutch Cannabis Potency to be restricted
Canadian Research
