Cannabidiol may be effective in halving the severity of symptoms and impairment caused by chronic anxiety, an Orygen pilot study has shown.
The Cannabidiol Youth Anxiety Pilot Study found that young people with treatment-resistant anxiety had an average 42.6 per cent reduction in anxiety severity and impairment following 12 weeks’ treatment with cannabidiol – a non-intoxicating component of the Cannabis sativa plant which is often referred to as CBD.
Orygen’s Professor Paul Amminger, who led the study, said this level of improvement was remarkable.
“The young people had fewer panic attacks and could do things which they were previously unable to do like leave the house, go to school, participate in social situations, eat at restaurants, take public transport or attend appointments by themselves,” Professor Amminger said of the findings published in the Journal of Clinical Psychiatry.
“That's an amazing change in the group which has had treatment-resistant, long-standing severe to very severe anxiety.”
The reduction in symptoms was observed on two different scales: a clinician rated scale (the Hamilton Anxiety Rating, 50.7 per cent) and a self-rated scale (the Overall Anxiety Severity and Impairment Scale, 42.6 per cent), which involved participants filling in a questionnaire on symptoms such as panic attacks, situational anxieties, worries and flashbacks.
Study co-investigator and Orygen Executive Director, Professor Patrick McGorry said the findings held promise for a significant number of young people, with Australian Bureau of Statistics data released on 22 July showing anxiety was the most common form of mental ill-health in young people, affecting nearly a third (31.5 per cent) of those aged 16–24 – almost double the rate of the general population.
“We’re seeing more and more young people experiencing anxiety – it’s the fasting growing form of mental ill-health in young people and we urgently need innovation in treatment. Cannabidiol is a promising treatment option which appears safe and effective. We need further research to confirm this and explore its value,” Professor McGorry said.
The pilot study involved 31 participants aged 12–25 who were recruited from Orygen’s primary care services. The participants had a diagnosed anxiety disorder and had failed to show significant improvement in anxiety severity following at least five cognitive behavioural therapy (CBT) sessions.
“The problem with current frontline treatments for anxiety – CBT and selective serotonin reuptake inhibitor (SSRI) antidepressant drugs – is that they only work in about half of the people who try them,(1, 2)” Professor Amminger said.
“Anxiety disorders are very common so that leaves a large number of young people untreated, struggling with symptoms and developing secondary conditions, for instance depression and substance use disorders.”
Orygen started exploring cannabidiol as an anxiety treatment after it was found to be effective in reducing anxiety in adults.(3, 4, 5, 6)
In Australia, cannabidiol has been approved by the Therapeutic Goods Administration as a treatment for children with rare forms of epilepsy (Dravet syndrome and Lennox Gastaut syndrome).(7) Cannabidiol has been approved for clinical trials as a treatment for children in Australia with Tourette Syndrome, Fragile X syndrome, autism spectrum disorder and intellectual disability.(8)
“It’s important to stress that cannabidiol does not induce any significant side effects or lead to the emergence of any neurological or psychiatric manifestations,” Professor Amminger said.
“Cannabidiol is non-intoxicating and doesn’t contain tetrahydrocannabinol (THC) so it doesn’t cause alterations in thinking and perception, it doesn’t make you ‘high’ and it’s not addictive. In fact, cannabidiol has been used to treat addictive behaviours in other research trials and can reduced some of the adverse and intoxicating effects of THC.(9)”
Pilot study participants’ starting dose was one 200mg capsule of cannabidiol per day, which was increased to 400mg after one week. Those who did not show significant improvement in anxiety symptoms had their dosage increased at 200mg increments up to 800mg per day. All participants were offered biweekly CBT for 12 weeks (five sessions).
“Our pilot study found that cannabidiol not only helped to reduce anxiety symptoms but it was also very well tolerated – the most common side-effects were mild sedation and mild fatigue but that was at the time when doses were increased and usually went away after a couple of days,” Professor Amminger said.
“We did not see side-effects like suicidal thoughts, irritability or sleep problems, which are not uncommon in people taking SSRIs.”
Although the findings are promising, further research is required.
“An open-label pilot study is limited by its design. To see a treatment effect in the treatment-resistant group is encouraging, but it could still be a placebo effect,” Professor Amminger said.
"The next step is a randomised controlled trial, which is the gold standard to test a new intervention. Such a trial needs to be done in a much larger group – around 200 to 250 young people – to enable us to say with some certainty that there is, or is not, real treatment benefits and effects."
The trial received financial and specialist technical support from the Lambert Initiative for Cannabinoid Therapeutics at the University of Sydney, a philanthropically-funded research program specialising in the development of cannabis-based therapies to alleviate human suffering.
What is cannabidiol?
- Cannabidiol is a non-intoxicating component of the Cannabis sativa plant. This means it does not cause alterations in thinking and perception, such as those caused by tetrahydrocannabinol (THC).
- Cannabidiol is not the same as cannabis. Cannabidiol is a component that is enriched in the “hemp” strains of cannabis. Unlike other substances found in the cannabis plant (for example, tetrahydrocannabinol (THC)), cannabidiol does not get you ‘high’.
- Cannabidiol is often referred to as CBD.
- Cannabidiol is not addictive. In fact, there is emerging evidence that it may help to treat addiction to other drugs such as alcohol, methamphetamine and high-THC cannabis.(9)
- Cannabidiol does not induce any significant side effects or lead to the emergence of any neurological, psychiatric or general clinical manifestations.(12)
- Cannabidiol has been tested in healthy research participants and in adults with anxiety disorders. In these studies cannabidiol has been found to reduce anxiety.(3, 4, 5, 6)
- The cannabidiol in this trial was supplied by Biosynthesis Pharma Group (BSPG). BSPG’s cannabidiol is purified to more than 99.5 per cent.
What did the pilot study involve?
The Cannabidiol Youth Anxiety Pilot Study (CAPS) was a 12-week open-label trial to test the feasibility, safety, tolerability and therapeutic effects of cannabidiol in reducing anxiety severity in young people.
The 31 participants recruited to the trial:
- were clients of Orygen’s primary care services
- were aged between 12 and 25 years (inclusive)
- had a diagnosed anxiety disorder
- had failed to show significant improvement in anxiety severity after five cognitive behavioural therapy (CBT) sessions that calendar year.
Participants started on a dose of one 200mg capsule of cannabidiol per day, which was increased to 400mg after one week. Those who did not show significant improvement in anxiety symptoms had their dosage increased at 200mg increments up to 800mg per day.
All participants were offered biweekly cognitive behavioural therapy (CBT) for 12 weeks (five sessions).
Why run the pilot study?
- Anxiety is the most common mental health condition in young people and affects up to 31.5 per cent of the Australian population.(10)
- Treatments for anxiety disorders include CBT and medications that increase serotonin levels in the brain but they do not work for everyone.
- In fact, only about 50 per cent of young people fully recover from anxiety disorders with current treatments.(1, 2) The remainder continue to experience symptoms that interfere with their life, work and education.
- Cannabidiol has been tested in healthy research participants and adults with anxiety disorder. In these studies cannabidiol has been found to reduce anxiety.(3, 4, 5, 6) The purpose of Orygen’s pilot study was to test the feasibility, safety, tolerability and therapeutic effects of cannabidiol in reducing anxiety severity in young people.
What is anxiety?
Anxiety disorders are characterised by persistent feelings of being anxious, that may have no obvious reason or cause. For people who suffer from anxiety, these feelings can be difficult to control. Although feeling anxious is a common response to a situation where we feel under pressure, if such feelings persist or occur suddenly in the absence of a stimulus, this can be quite disabling and may require support or treatment.
What does it mean to have anxiety?
Although some people may experience only mild anxiety, more severe anxiety often interferes with people’s lives and can be associated with palpitations (pounding heart or accelerated heart rate), panic, feeling detached from oneself, sweating, trembling, shortness of breath or chest pain.
How common is anxiety?
Anxiety is the most common mental health condition in young people and affects up to 31.5 per cent of the Australian population.(10)
1. James AC, James G, Cowdrey FA, Soler A, Choke A. Cognitive behavioural therapy for anxiety disorders in children and adolescents. Cochrane database of systematic reviews (Online); 2015. p. CD004690.
2. Strawn JR, Welge JA, Wehry AM, Keenshin B, Rynn MA. Efficacy and tolerability of antidepressants in pediatric anxiety disorders: a systematic review and meta-analysis. Depress Anxiety; 2015. p. 149-57.
3. Bergamaschi MM, Queiroz RHC, Chagas MHN, et al. Cannabidiol Reduces the Anxiety Induced by Simulated Public Speaking in Treatment-Na&iuml;ve Social Phobia Patients. Neuropsychopharmacology: Nature Publishing Group; 2011. p. 1219-26.
4. Zuardi AW, Cosme RA, Graeff FG, Guimarães FS. Effects of ipsapirone and cannabidiol on human experimental anxiety. J Psychopharmacol (Oxford); 1993. p. 82-8.
5. Crippa JAdS, Zuardi AW, Garrido GEJ, et al. Effects of cannabidiol (CBD) on regional cerebral blood flow. Neuropsychopharmacology; 2004. p. 417-26.
6. Crippa JAS, Derenusson GN, Ferrari TB, et al. Neural basis of anxiolytic effects of cannabidiol (CBD) in generalized social anxiety disorder: a preliminary report. J Psychopharmacol (Oxford); 2011. p. 121-30.
7. Therapeutic Goods Administration. Prescription medicines: registration of new chemical entities in Australia, September 2020. Available from: https://www.tga.gov.au/prescription-medicines-registration-new-chemical-entities-australia
8. Australian New Zealand Clinical Trials Registry. Trial Search: cannabidiol. 2022. Available from: https://anzctr.org.au/TrialSearch.aspx
9. Jutras-Aswad D, Prud’homme M, Cata R. Cannabidiol as an Intervention for Addictive Behaviors: A Systematic Review of the Evidence. SART; 2015. p. 33.
10. AIHW. Mental health: prevalence and impact. 2022. Available from: https://www.aihw.gov.au/reports/mental-health-services/mental-health