Weekly Cannabis Science News


Stay up to date with our CBD and medicinal cannabis timeline

By Dr Julie Moltke

July 10

Researchers have found that CBD has antibiotic properties.

In a new scientific study, a team of Australian scientists have found that Cannabidiol (CBD), the most well-known of the 144 cannabinoids from the cannabis plant, might one day be used as an antibiotic drug. The study was carried out on a specific type of gram-positive bacteria called staphylococcus aureus that is dreaded for its ability to become multi-resistant to antibiotics (MRSA). CBD killed all strains of the bacteria produced in the laboratory, including the most resistant ones that are often difficult to kill with standard antibiotics. This seems promising considering that drug-resistant bacterias are posing a significant threat all over the world. CBD was also shown to combat skin infections in mice.

The findings were presented at the annual conference of the American Society for Microbiology San Francisco, even before being published in a peer-reviewed study. Study leader Mark Blaskovich said that this is only the very early research stages and more studies need to be carried out to make any conclusions. Asked about if you can substitute antibiotics for CBD he answered: "Don't! Most of what we have shown has been done in test tubes—it needs a lot more work to show it would be useful to treat infections in humans."

The results are expected to be published in a peer-reviewed study later this year.

July 2

Cannabis potency has more than doubled in 10 years in Europe.

The European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) has released a report about the development in the European cannabis market. The report outlines the existing and emerging products on the illicit and the legal market in Europe (3). Approximately 1% of the adult European population between 15-64 years uses cannabis daily, and it is estimated that around 17,5 million Europeans between 15-34 years of age have used cannabis in the last year (4). In the report, you can read that the THC levels in both herbal cannabis (flower) and cannabis resin (hash) have increased over the last decade.

Herbal cannabis had an average potency of 5% THC in 2006, and in 2016 it had doubled to 10%. The numbers are similar for cannabis resin with an increase from 8% THC in 2016 to 17% in 2016. This is alarming as adverse mental health effects are associated with higher levels of THC. The report is also stressing the fact that with the emerging European medical cannabis market, and the booming of CBD as a food-supplement the dynamics of the European market are becoming more complex and that we need more assessment tools to monitor the development of the market.

June 17

A new study shows that CBD can help reduce anxiety in psychiatric patients.

A psychiatric clinic has revealed a relatively big retrospective case report where CBD was added as adjunct to the usual treatment to improve anxiety and sleep in 72 patients. Results showed decreased anxiety scores in 80% of the patients after the first month of the study and it remained decreased during the rest of the study period. 67% of patients had decreased anxiety scores after one month even though they fluctuated over time (2).

This study looks promising for CBD as an additional treatment to help psychiatric patients reduce anxiety and improve sleep. We are still lacking clinical trials investigating how CBD works on healthy individuals who are not taking any other medications, but who suffer from insomnia.

June 11

A New study suggests that CBD has no negative long-term effect on learning and memory

A new animal study of long term cannabidiol treatment in mice shows no adverse effect on motor performance, spatial learning and long-term memory. This suggests that there are no measurable side effects of long-term treatment with CBD in mice. We still need to see these findings replicated in human clinical trials, but it does support the common understanding that CBD might be a safe treatment for a variety of conditions in the future (1).



(1) Schleicher, E. M., Ott, F. W., Müller, M., Silcher, B., Sichler, M. E., Löw, M. J. Bouter, Y. (2019). Prolonged Cannabidiol Treatment Lacks on Detrimental Effects on Memory, Motor Performance and Anxiety in C57BL/6J Mice. Frontiers in Behavioral Neuroscience, 13, 94. https://doi.org/10.3389/fnbeh.2019.00094

2) Shannon, S., Lewis, N., Lee, H., & Hughes, S. (2019). Cannabidiol in Anxiety and Sleep: A Large Case Series. The Permanente Journal, 23, 18–041. https://doi.org/10.7812/TPP/18-041

(3) Developments in the European cannabis market, EMCDDA Papers — www.emcdda.europa.eu/publications/emcdda-papers/developments-in-the-european-cannabis-market

(4) European Drug Report 2019 — www.emcdda.europa.eu/edr2019