The connection of High strength cannabis with addiction and mental health problems

Researchers from the Addiction and Mental Health Group at the University of Bath (UK) systematically analyzed the relationship between the types of cannabis people use and their addiction and mental health problems. Their work draws on 20 studies involving almost 120,000 people.

Cannabis potency refers to the concentration of tetrahydrocannabinol (THC) in cannabis - the key psychoactive drug it contains. Recent studies from the same team at Bath have found that the concentration of THC in cannabis has increased significantly over time meaning that cannabis used today is typically much stronger than previously.

The new study, published in The Lancet Psychiatry, suggests that people who use high potency cannabis are more likely to experience addiction than those using low potency products. It also suggests that people using high potency cannabis are more likely to experience a psychotic disorder, such as schizophrenia.

These findings may help to explain why more people have received treatment for cannabis problems over recent years. Data from the European Monitoring Centre for Drugs and Drug Addiction show a 76% increase in people entering treatment for cannabis addiction in the past decade.

Based on these new results, the authors argue that public health guidelines and policies to help make cannabis use safer should be encouraged.

Lead author, Kat Petrilli from the University of Bath's Department of Psychology explained: "Our systematic review found that people who use higher potency cannabis could be at increased risks of addiction as well as psychosis when compared to people who use cannabis products with lower potencies.

The authors point out that strategies to make cannabis use safer could inform how the drug is regulated in the UK and internationally. Recreational cannabis use remains illegal in the UK, but cannabis products are now legally sold for recreational use in Canada, Uruguay, and parts of the USA.

Several other countries appear set to follow this trend, including Germany. In the UK, the Liberal Democrats have argued that a legally regulated market could make cannabis use safer by enforcing a limit on the potency of cannabis products and investing the revenue and savings from this into education and treatment for cannabis problems.

Ref: Kat Petrilli, Shelan Ofori, Lindsey Hines, et. al, Association of cannabis potency with mental ill health and addiction: a systematic review. The Lancet Psychiatry, Published: July 25, 2022,  DOI:https://doi.org/10.1016/S2215-0366(22)00161-4