Standard units for cannabis consumption could improve mental health outcomes

Researchers have suggested that a standard unit grading system for the potency of cannabis would result in significant improvements to the mental health of people who use the drug.

It is claimed that a grading system, similar to those used for alcohol consumption, would make people more aware of the levels of THC – the main psychoactive component – in the cannabis they are consuming.

Writing in the journal Addiction, members of the Addiction and Mental Health Group at the University of Bath, staff from King’s College London, UCL and the Australian Catholic University in Melbourne, suggest a unit level should be set at 5mg of THC – the amount that would typically be found in a small joint. This, according to the researchers, is enough to induce intoxication but minimise the possibility of psychotic symptoms.

Lead author Sam Craft, from King’s College London, said:

“Our findings add to a growing body of evidence that suggests the health effects of cannabis are dose-related.

“We believe a unit system would help both users and healthcare professionals by providing clearer information on the types of cannabis products and their strength.”

The publication coincides with a second study from the team, published in the journal Psychological Medicine, which examines the relationship between cannabis and key health outcomes in more than 55,000 people across 175 countries.