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ACU research leads to a new standard dose in cannabis research

The work of ACU neuroscientist Valentina Lorenzetti has led the top US federal health agency to announce a new standard dose of delta-9-tetrahydrocannabinol (THC) - the main chemical responsible for the psychotropic and addictive properties of cannabis.

The standard dose will be used by researchers to enable more accurate and useful research into the effects of cannabis use.

The National Institute on Drug Abuse (NIDA) has advised researchers of the new requirement to measure and report results using a standard THC unit of five milligrams in all human subjects’ research.

Dr Lorenzetti, the deputy director of the newly-launched Healthy Brain and Mind Research Centre, and Dr Tom Freeman from the University of Bath called for the new measure in the journal Addiction in 2019.

As cannabis becomes more available and social use increases among young people, Dr Lorenzetti said more research on the drug’s effects was needed to understand the impact of acute and long-term THC exposure, prenatal and adolescent use on brain development, cognition, and educational outcomes.

However, the lack of a standard unit of THC exposure has so far made it difficult to measure cannabis intake and compare its effects across studies.

“It is often hard to interpret existing data due to the wide variability in potency of cannabis plant material, cannabis products and extracts, the lack of standard measures of use, and the different ways people consume cannabis,” she said.

“Having a standardised measure of THC in cannabis products enhances our ability to compare studies on its adverse effects and benefits.”

Dr Lorenzetti said THC’s effects vary based on how it is taken and the tolerance of the user. Having a standard unit of measurement will make it easier to compare the influence of these factors on how individuals respond to the drug. 

Cannabis contains more than 500 chemicals, and more than 100 cannabinoids. THC is the main cannabinoid responsible for the “high” that users seek, as well as some of the medicinal effects demonstrated in clinical trials.

The NIDA has said the standard unit is simply a unit of measure to improve cannabis research - not a limit or a recommendation for consumption that would apply to consumers or to dispensaries. 

Similar standard measures have also been applied to other substances - such as alcohol being defined by a standard drink. Researchers also use morphine milligram equivalents to compare effects of opioids that have widely varying potencies.

The change has also been endorsed by the US National Heart, Lung, and Blood Institute (NHLBI), National Institute of Mental Health (NIMH), National Cancer Institute (NCI).

ACU’s newly launched Healthy Brain and Mind Research Centre aims to advance knowledge critical to improving mental health, participation, and well-being.

Media Contact: Elisabeth Tarica on 0418 756 941 or elisabeth.tarica@acu.edu.au