Project ID NS-MH2024_41


Co Supervisor 1A Institute of Psychiatry, Psychology & Neuroscience, School of Mental Health & Psychological Sciences, Department of PsychologyWebsite

Co Supervisor 1B Institute of Psychiatry, Psychology & Neuroscience, School of Academic Psychiatry, Department of Psychological MedicineWebsite

Exploring the anxiolytic effects of cannabis based medicinal products (CBMPs)

The anxiolytic effects of cannabis based medicinal products (CBMPs) have been touted for decades. Medical cannabis was legalised in the UK in November 2018 and observational, prospective studies of private prescriptions have demonstrated that patients taking CBMPs show significant reductions in anxiety. CBMPs vary in cannabinoid content, including their cannabidiol (CBD) & delta-9-tetrahydrocannabinol (THC) content and formulation (e.g. oil, oral capsule, vaporised flower). There is promising evidence that CBD may reduce social anxiety following a single dose in laboratory-models and following four weeks of daily treatment. However, more research is needed to unpack the separate and combined anxiolytic effects of CBD and THC.

The overarching aims of the project are: (1) understand the long-term, real-world associations between use of different CBMPs and anxiety outcomes; (2) test the separate and combined acute effects of CBD and THC on state anxiety in vulnerable individuals.

Research plan
Study 1 (Year 1): meta-analysis of CBD’s anxiolytic effects in the lab and meta-analysis of prospective associations between CBMP usage and reduced anxiety.
Study 2 (Year 1 & 2): mega-analysis of combined prospective, observational studies tracking CBMP patients’ anxiety levels, moderated by CBMP type.
Study 3 (Years 2 & 3): a randomised, placebo-controlled, double-blind, crossover, non-CTIMP experiment comparing the one-off effects of: placebo, oral CBD (800mg), dronabinol (oral THC, 5mg), and CBD (800mg) + dronabinol (5mg), on laboratory measures of anxiety (including a social stress test) in participants (n=24) with high, subclinical baseline anxiety.

Translation to the clinic:
• Collaborate with clinicians
• Conduct public & patient involvement (PPI) in people with anxiety
• Results will inform a clinical trial application

Techniques: meta-analysis, longitudinal data analysis, multilevel modelling, RStudio, randomised controlled trial, psychopharmacology

Representative Publications

Rifkin-Zybutz, R., Erridge, S., Holvey, C., Coomber, R., Gaffney, J., Lawn, W., … & Sodergren, M. H. (2023). Clinical outcome data of anxiety patients treated with cannabis-based medicinal products in the United Kingdom: a cohort study from the UK Medical Cannabis Registry. Psychopharmacology, 1-11.

Lawn, W., Trinci, K., Mokrysz, C., Borissova, A., Ofori, S., Petrilli, K., … & Curran, H. V. (2023). The acute effects of cannabis with and without cannabidiol in adults and adolescents: A randomised, double?blind, placebo?controlled, crossover experiment. Addiction.

Lawn, W., Hill, J., Hindocha, C., Yim, J., Yamamori, Y., Jones, G., … & Bloomfield, M. A. (2020). The acute effects of cannabidiol on the neural correlates of reward anticipation and feedback in healthy volunteers. Journal of Psychopharmacology, 34(9), 969-980.

Erridge, S., Salazar, O., Kawka, M., Holvey, C., Coomber, R., Usmani, A., Rucker, J. … & Sodergren, M. H. (2021). An initial analysis of the UK Medical Cannabis Registry: Outcomes analysis of first 129 patients. Neuropsychopharmacology reports, 41(3), 362-370.

Erridge, S., Kerr-Gaffney, J., Holvey, C., Coomber, R., Barros, D. A. R., Bhoskar, U., … & Rucker, J. (2022). Clinical outcome analysis of patients with autism spectrum disorder: analysis from the UK Medical Cannabis Registry. Therapeutic Advances in Psychopharmacology, 12, 20451253221116240.

Carhart-Harris, R. L., Bolstridge, M., Day, C. M., Rucker, J., Watts, R., Erritzoe, D. E., … & Nutt, D. J. (2018). Psilocybin with psychological support for treatment-resistant depression: six-month follow-up. Psychopharmacology, 235, 399-408.