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Preliminary findings from T21 Australia

illustration of Australia and cannabis

An observational study of patients prescribed medicinal Cannabis for chronic pain, anxiety, posttraumatic stress disorder and multiple sclerosis


Kylie O’Brien, Justin Beilby, Michelle Frans, Michael Lynskey, Michael Barnes, Mihindu Jayasuriya, Alkyoni Athanasiou-Fragkouli, Philip Blair and David Nutt


March 20th, 2023


Since medical access to medicinal cannabis (MC) was legalised in Australia in 2016, numbers of people prescribed MC have increased exponentially. There is a need for safety and effectiveness data on the longer-term use of MC in real-world settings. This paper describes the methodology of T21 Australia, an observational study that commenced early in 2022 and its preliminary findings.


This study tests whether medicinal cannabis is effective in four primary conditions: chronic pain, anxiety, posttraumatic stress disorder and multiple sclerosis (MS). Participants are prescribed MC from within a Project Formulary, completing questionnaires at baseline then 3 monthly for up to 12 months.


Between the start of the study in February and 30 August 2022, 278 participants had been recruited into the study: 50.7% female, 48.2% male and 1.1% non-binary with average age 39.2 years (18–77). Patients reported a low quality of life and high levels of co-morbidity. Three-month data, available for 71 participants, indicate that MC was associated with substantial improvements in self-reported quality of life, general health, mood/depression and sleep with standardised effect size estimates ranging from 0.57 to 0.93. Three adverse reactions were reported.


This paper describes the protocol used for an observational study conducted in Australia assessing the effectiveness of MC in four main conditions. We have established the feasibility of collecting real-world data on symptoms and quality of life in people receiving treatment with MC. Preliminary evidence suggests that MC may be effective in improving quality of life, general health, mood and sleep.

This research was published in the Drug Science, Policy and Law Journal the definitive source of evidence-based information and comment for academics, scientists, policymakers, frontline workers and the general public on drugs and related issues

For open-access to the full report of this research, see below:

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