Medicinal Use of Psilocybin: Reducing restrictions on research and treatment
The Adam Smith Institute, in conjunction with the Conservative Drug Policy Reform Group (CDPRG), has published a new report outlining the medical potential of psilocybin and the need to reduce restrictions on research and treatment written by Dr James Rucker, Dr Jesse Schnall, Dr Daniel D’Hotman, David King, Timmy Davis, and Professor Joanna Neill:
Psilocybin is a compound found in over 100 species of fungi. In humans, it induces temporary changes in mood, perception and cognition via activation of serotonin receptors in the brain. It is associated with a low potential for harm relative to other classes of psychoactive drugs: it has very low toxicity, its use is not associated with the development of physical dependence, nor with acquisitive or other crime, and deaths attributed to its abuse are extraordinarily rare. It is listed in Class A of the Misuse of Drugs Act 1971 and in Schedule 1 of the Misuse of Drugs Regulations 2001. There is overwhelming scientific consensus that the current legal status of psilocybin is not evidence-based, but rather grounded in overstated historical assumptions of harm.
Depression is among the most significant social, economic and medical challenges in the UK. It is the greatest contributing factor to suicide, a leading cause of disability, and it costs the economy £10 billion annually. Existing therapies are not adequate for approximately 30% of patients; 1.2 million British residents are estimated to be living with treatment-resistant depression. Since very few advances have been made in the treatment of depression in several decades, there is an urgent need to support research into novel therapies for treatment-resistant cases.
Psilocybin is being investigated as a novel therapy for treatment-resistant depression and other difficult-to-manage mental health conditions, including obsessive-compulsive disorder, substance misuse disorders, and end-of-life anxiety. In 2018, the British life sciences company Compass Pathways received FDA ‘Breakthrough Therapy’ designation for psilocybin. Evidence from completed early phase trials indicates that psilocybin can be used safely and feasibly, is well tolerated by patients, and that it is likely to have lasting therapeutic benefits. However, robust evidence on efficacy can only be generated by large-scale phase 3 controlled clinical trials. Compass intend to start phase 3 at UK sites in the near future. These trials will be greatly enabled by rescheduling.
Although trials are successfully being undertaken, Schedule 1 regulations are a major barrier, increasing the costs, difficulties and duration of research. Schedule 1 research typically requires multiple Home Office licenses per study, incurring significant administrative costs and delays. Compliance with Schedule 1 safe custody and security regulations add further substantial burdens of cost and time. In practice, these requirements necessitate contracting specialised pharmacies to do what could otherwise be done by hospital pharmacies at trial sites. Additionally, stigma associated with Schedule 1 negatively impacts funding, ethical approval, and collaboration. These barriers, which are well known among the research community and have been recognised in Parliamentary reports for at least twenty years, prevent many studies from taking place and substantially complicate those that do.
A scheduling review is undertaken as part of the normal process when a medicinal product achieves market authorisation, but significant savings could be made by moving psilocybin to Schedule 2 prior to the commencement of phase 3 trials. This would have wide-ranging benefits: to legitimate commercial drug development through reduced barriers to research; to the taxpayer through decreased expenditure of Government research grants; and to the NHS and British patients through lower end-costs of treatment and earlier completion of trials. Greater regulatory support for psilocybin research will ensure the UK’s reputation as a global centre of excellence in this area, attract commercial investment and international expertise, and prevent a ‘brain-drain’ of British research and innovation to other jurisdictions. Immediate action will yield the greatest benefits to the UK.
In November 2018, a precedent was set for moving controlled drugs (cannabis-based products for medicinal use (CBPM)) from Schedule 1 to Schedule 2 prior to market authorisation as a medicine. At the time, the Home Office wrote: “The rescheduling may lead to increased UK research [...] as these products can be tested more easily.” “This may lead to economic benefits for UK businesses and health benefits to patients if this research leads to new and improved [medicinal products].” “In principle, research is ongoing and could lead to more effective treatment, lower costs, better understanding and management of risks, and improved health and wellbeing, over the medium term.” The current Chief Medical Adviser to the UK Government, Prof Chris Whitty, later stated that moving CBPM to Schedule 2 was “the single most important thing that could be done by Government” to support the development of an evidence base.
Likewise, rescheduling would be the most significant and immediate way that Government could support ongoing research with psilocybin. Psilocybin could be rescheduled with statutory limits restricting access to ethically-approved research studies only – unless a product has market authorisation – thus preventing wider prescribing on an unlicensed basis. This would be unprecedented in UK law, but would serve to support scientific development without risking inappropriate prescribing.
The major source of diverted medicinal drugs is by prescription prior to diversion. Moving psilocybin to Schedule 2 for research purposes is unlikely to increase the risk of diversion because the drug is administered to participants under clinical supervision, rather than being prescribed for use in the community. This is in line with ACMD advice that “the risk of diversion and misuse in a research setting is likely to be minimal.”
The proposed research-only model of rescheduling would support legitimate scientific and commercial development while maintaining stricter controls on psilocybin than on other controlled drugs associated with greater potential for harm, including diamorphine (heroin), methamphetamine, and cocaine. It would not affect existing legal controls on criminal use or supply. This model may also serve as a basis for future scheduling decisions; there are other Schedule 1 drugs under investigation as treatments for mental health conditions for which there are similar clinical arguments to support rescheduling, albeit with less immediate urgency.
The ongoing ACMD review on barriers to research with Schedule 1 drugs is vital. We also welcome the current work to establish a Standard Operating Procedure (SOP) for scheduling decisions. However, the primary emphasis of the review on barriers to research is on synthetic cannabinoids and it is currently unclear whether the SOP will be used to review historical scheduling decisions. Since neither report is expected to be published until 2021, nor to directly provide recommendations on psilocybin, there is no known work currently commissioned by the Home Office that addresses the urgent issues identified in this report.
We recommend that the Home Office commission a high-priority ACMD review into the access-restricted rescheduling of psilocybin under the Misuse of Drugs Regulations 2001.