The Guardian 15 November 2020
Family First Comment: “In herbal cannabis, THC concentrations increased by 14% between 1970 and 2017. This was primarily due to a rising market share of stronger varieties, such as sinsemilla. Concentrations in cannabis resin, which is extracted from herbal cannabis, increased by 24% between 1975 and 2017.”
And with higher potency comes greater harm and addictions. This is not your parent’s pot. 
Concentrations of intoxicating THC have risen, data from more than 80,000 street drug samples gathered over 50 years shows.
Cannabis resin – or “hash” – has increased in strength by nearly 25% over the past half century, a major international study has revealed.
Researchers with the Addiction and Mental Health Group at the University of Bath analysed data from more than 80,000 cannabis street samples tested in the past 50 years in the US, UK, Netherlands, France, Denmark, Italy and New Zealand.
Their findings, published in the 
journal Addiction, reveal concentrations of THC – the intoxicating component of cannabis responsible for giving users a “high” – have changed over time.
In herbal cannabis, THC concentrations increased by 14% between 1970 and 2017. This was primarily due to a rising market share of stronger varieties, such as sinsemilla. Concentrations in cannabis resin, which is extracted from herbal cannabis, increased by 24% between 1975 and 2017.
This was the equivalent of a 5mg increase in THC per annum. One 5mg dose is enough for mild intoxication, according to the researchers.
“Cannabis has continued to increase in strength over time, such that today it differs enormously from the type of drug used by people 50 years ago,” said lead author Dr Tom Freeman. “During this time attitudes have also shifted. There is now a greater appreciation of its complex interplay with mental health and potential medicinal uses.”
READ MORE: https://www.theguardian.com/society/2020/nov/15/cannabis-resin-now-25-more-potent-global-study-reveals?CMP=Share_iOSApp_Other