One of the world's first clinical trials into the potential for psychedelic compound psilocybin to prevent disabling cluster headache will be funded through the Novel Treatments and Management Strategies for Chronic Pain stream of the Australian Medical Research Future Fund (MRFF). This is the first new approved trial for treatment of cluster headache - one of the most intensely painful human experiences - in at least two decades in Australia.1
Cluster headache is often colloquially referred to as 'suicide headache' due to its severity, which sufferers describe as a sharp, drilling pain behind the eye or temple.2 The attacks can occur as often as eight times a day and last for up to three hours, typically flaring up in regular, seasonal cycles unique to the individual.3 Cluster headache is often misdiagnosed, with an average delay of eight years to be identified, and has a significant impact on quality of life.3 Existing treatments for other types of headache, including new medicines for migraine, are less effective for cluster headache.
Led by Dr Faraidoon Haghdoost, former GP and Research Fellow specialising in headache disorders at The George Institute for Global Health and UNSW Sydney, the pilot 'Psilocybin Efficacy and Acceptability on Cluster Headache Episodes' (PEACE) pilot trial will assess whether 10 mg of psilocybin once a week for four weeks compared to placebo can prevent cluster headache attacks. The study builds on early patient reports and small-scale trials that indicate its potential benefits.4,5
"Some studies have shown psychedelics can have a 'cluster busting' effect, by reducing or eliminating attacks after just a few doses. But global clinical evidence for psilocybin is limited, and there are no data for Australia. With only a handful of preventive treatments for cluster headache-and verapamil, the first-line option, proving ineffective for more than half of patients-many people resort to self-medicating with treatments such as psilocybin from unregulated sources.
By:Dr Faraidoon Haghdoost
Research Fellow - Headache Disorders, The George Institute for Global Health
Involving clinicians, researchers, and consumer advocacy groups, the PEACE trial will also generate vital safety data, helping guide responsible use.
"Our trial aims to address some of the gaps and, importantly, to evaluate the risks, to inform an eventual pathway for official prescribing, and to reduce harm with current unregulated use.
If the PEACE findings are positive, we hope to do larger trials with the aim of providing an effective, evidence-based treatment option using affordable generic psilocybin, for those enduring cluster headache.
By:Dr Faraidoon Haghdoost
In 2023, Australia became the first country to legalise psilocybin, allowing specially trained psychiatrists (Authorised Prescribers) to prescribe it for controlled clinical use in treatment-resistant depression.6
References
1. Burish MJ, Pearson SM, Shapiro RE, Zhang W, Schor LI. Cluster headache is one of the most intensely painful human conditions: Results from the International Cluster Headache Questionnaire. Headache: The Journal of Head and Face Pain. 2020 Dec 18;61(1):117-24
2. Fletcher J. Why Cluster Headaches Are Called "Suicide Headaches." Journal of Neurology & Stroke. 2015 Nov 13;3(3)
3. Ray JC, Stark RJ, Hutton EJ. Cluster headache in adults. Australian Prescriber. 2022 Feb 1;45(1):15-20
4. Sewell RA, Halpern JH, Pope HG. Response of cluster headache to psilocybin and LSD. Neurology. 2006 Jun 26;66(12):1920-2
5. Tracy L. Promising Signs for Psychedelic Use in Cluster Headache [Internet]. Migraine Science Collaborative. 2023. https://migrainecollaborative.org/promising-signs-for-psychedelic-use-in-cluster-headache
6. Therapeutic Goods Administration (TGA). Update on MDMA and psilocybin access and safeguards from 1 July 2023 [Internet]. 2023. www.tga.gov.au/news/news/update-mdma-and-psilocybin-access-and-safeguards-1-july-2023
